The Importance of Welding Electrode Flux Coating

Air
Separation
Plant
Welding electrode flux coating
- Importance of -
By JGC Annamalai
(Relevance to AWS A5.1)
1

Page
A 1 Chapters / Topics List 2
A 2 Welding or Joining, Great Evidences 3
A 3 Developments in Welding 5
A 4 SMAW, Classification of Welding Electrode 6
A 5 SMAW, Selection of Welding Electrodes 11
A 6 SMAW, Function and Importance of Flux on Electrode Coating 23
A 7 SMAW, Electrode Flux Ingredients and their proportions 28
A 8 SMAW, Production of Welding Electrodes 33
A 9 SMAW, Welding Electrode Requirements, Testing, Qualification (AWS A5.1) 36
A 10 SMAW Welding Electrodes for Stainless Steels (AWS A5.4) 42
A 11 SMAW Welding Electrodes for Low Alloy Steels (AWS A5.5) 46
A 12 Tips on Welding Electrodes 54
Annexure List
AA 1 List of Flux ingredients 55
AA 2 Welding Positions per ASME Sec IX 56
AA 3 AWS A5.1 recommended Welding Currents 57
AA 4 AWS Spec List for Welding Consumables 59
AA 5 History, Timeline, Events & Mile-Stone Developments in Welding 60
AA 6 Recent Advances in Welding 64
AA 7 Moisture in SMAW Electrodes, Effects and Control 69
AA 8 Welding Temperature Distribution (contour) (for CS, SS, Aluminum) 75
AA 9 CS, SS Weld & Casting Solidification-Hot Cracking & its Control 77
AA 10 Welding Terms & Glossary 98
Importance of Welding Electrode Flux (relevance to AWS A5.1)
Authored by R.Annamalai, (former Chief Equipment Engineer, JGC Corporation), rannamalai.jgc@gmail.com
Chapters / Topics List:
Chapter-1
By JGC Annamalai
Total Pages - 105
2

Great Evidences in the Development of Welding
Chapter-2
By JGC Annamalai
3

Great Evidences in the Development of Welding
Chapter-2
By JGC Annamalai
Pg.A2.2
4

(1).
(2).
(3).
Some of the well known Electrode Manufacturers are:
Detailed Welding History or Timeline on Welding Developments are found in the attachment(AA5).
Earliest Filler Metal Specifications (first issued as ASTM A233-40T and issued as AWS A5.1, from 1969, by AWS):
1940, ASTM A 233-40T : The initial 1940 document and the three revisions within the next five years were prepared by a
joint committee of the American Society for Testing and Materials(ASTM) and the American Welding Society(AWS).
However, between 1940 and 1948, they were issued only as an ASTM specification.
1948 revision was the first specification issued with the AWS designation appearing on the document.
1969 revision was the first time that the document was issued without the ASTM designation.
However, Lincoln Electric sued A.O. Smith on Electrode Patent and won.
Quality level of present day electrodes, had reached a fairly satisfactory stage. Now, we see, if we adhere to the following
points, defects are under control and the weld defects are either nil or within acceptable limits.
(1). The welding is done following the qualified Welding Procedure
(2). Electrodes are stored and used following the Welding Electrode manufacturers' recommendations.
(3). The base metal is cleaned and free of organic materials, paints, grease, oil, water, rust etc. The base metal is
free of surface defects, like porosity, laminations, the material is homogeneous (spread of chemical elements
uniformly). No welding is allowed, during high wind and rain.
(4). Proper welding grooves/bevels are followed. The groove and gap shapes and dimensional tolerances are
within limits.
(5). Welders are skilled and should have eagerness to maintain continuous quality level and know to use proper
electrodes and know to skim the weld puddle and maintain constant arc length and control the bead size and
shape and they are able to move the weld tip such that the slag is floating.
However, Science believes or trusts only recorded and proven evidences and published reports.
Between 1920 to 1927, A.O. Smith Corporation(USA) developed an electrode spirally wrapped with paper, soaked in
sodium silicate, and then baked. This was the first of the cellulosic type electrodes. Smith Corporation established better
method of coating by extruding over the core wire. This method allowed the addition of other flux ingredients to further
improve or modify the weld metal.
(1). Lincoln Electric Company, USA , (2). Oerlikon Welding Electrodes, Switzerland, (3). D&H Secheron Welding
Electrodes, India, (4). Philips Welding Electrodes, Netherlands, (5). Kobe Steel Welding Electrodes, Japan, (6). Esab
Welding Electrodes, Sweeden, (7). Hobart Welding Electrodes, USA, (8). Miller Electrodes, USA
Story related to Flux coating application-1: Initial Days, welders were using bare metal welding electrodes, in
open yards. Some rods fell on the wet ground during welding and the wet mud was coated on the electrode.
When the welder used the dried, mud coated electrode(titania, lime ?), the welders found the arc was more stable
and the weld was having less spatter and lesser porosity. Later, the welders investigated and found, change is
due to the mud deposit on the bare electrodes. Later, it lead to the flux coating.
Story related to Flux coating application-2 : Bare metal rods were stacked on the open place. Due to rain, the rods
were rusted. Welders started using the rusted(iron oxide(rust) coated) rods and the welders found the welding
was more stable and the welding was having fewer spatters and lesser porosity. Later it lead to the flux coating.
Story related to Flux coating application-3: Welders were also happy that an improved weld could be made by
(1). wrapping the rod in newspaper or
(2). by welding adjacent to a pine board/stick placed close to and parallel with the weld being made.
In these cases, some degree of shielding the arc from the atmosphere was being accomplished. These early days
observations led to the development of the coated electrode.
Earlier , Flux Coating Developments
These stories are found in old books on Welding: (Even now, we may see, in remote places and villages, welding is done
Even now, we may see, in remote places and villages, welding is done using bare cables from transformers/ Generators
to work location and also people using bare metal welding rods/electrodes. Probably, it is acceptable for their service.
Quality conscious people always insist the use of coated electrodes as mandatory for normal and critical work.
Electrode Invention, Stories:
SMAW(Shielded Metal Arc Welding) Electrodes : Other names, Flux coated Electrodes or Covered Electrodes or Coated
Electrodes or MMA, Welding Electrodes or Stick (Welding) Electrodes or Clay Electrodes
Welding & SMAW Electrodes - Developments
Chapter-3
Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts
together and allowing them to cool, causing fusion.
SMAW is a Welding process which occurs when an arc is established between the flux covered welding electrode and base
metal. The heat from electric arc will decompose the flux ingredients as well as melt the core rod and transfer the molten
metal and slag through the arc. These combine the molten base metal to form the weld metal with a protective slag layer on
top. Shielding gases that displace the air from the weld zone are generated in the decomposition of the flux ingredients.
By JGC Annamalai
5

(1).
(2)
.
(3)
.
(4).
Third digit - Welding Positions :
There are four basic positions, like Flat, Horizontal, Vertical and
Overhead.
Flat Position - a position of welding in which the filler metal is posited from the upper side of the joint with the face
of the weld horizontal. The welding end of the electrode is normally pointed downward.
Horizontal Position - A position of welding in which the weld is deposited up the upper side of a horizontal surface
and against a vertical surface. The welding end of the electrode is normally positioned, at the side of a vertical wall
Vertical Position – A position of welding in which the line of welding is in a vertical plane and deposited up on a
vertical surface
Overhead position – A position of welding in which the weld is deposited from the under side of the joint and the
face of the weld is horizontal.
(sample positions, as shown in the ASME Sec IX, is attached (a). for groove welds on plates & pipes and (b). for
fillet welds on plates & structural shapes). Please check with ASME Sec IX or other Codes for the allowable
variations in Positions.
Per ASME Sec IX, welder qualified on pipe, with 6G position, qualifies the welder to weld on all positions of pipe,
plates and structurals. So, most of the Companies used to have their welders qualified per ASME Sec IX, with pipe
Position in 6G. Thickness qualified is T, allowed to weld is 2T; Qualified on 6" pipe allow to weld pipe all ≥ 2 1/2"
Chapter-4 SMAW Electrodes, Classification
SMAW Electrodes : Other names are : Coated Electrodes, Covered Electrodes, Stick Electrodes, MMA Electrodes
(Material wise , they are classified: as Carbon Steel, Low Alloy Steel, Stainless Steel Electrodes etc.)
Fourth Digit - Flux Type :
SMAW- The electrode classification based
on flux coverings are Cellulose or Wood
Pulp type, Rutile or Titania type, Low
Hydrogen or Lime tipe and Iron Oxide type
(Here, we give only limited info. For more specifiation details, please refer to original AWS A5.1)
SMAW covered welding electrodes are identified with 4
digit letter with prefix "E".
"E" represents Electrode.
First 2 digits(like60 or 70) represents, the tensile
strength, in 1000 psi
3rd digit(like 1,2,3,4; 1 for all position, 2, for Horizontal
and flat position, 3 for Flat position,4 for Flat, Overhead,
Horizontal, Vertical-Down) represents the welding position
4th digit(like 0,1 for Cellulose, 2,3,4,9 for Rutile, 5,6,8 for
Lime/low hydrogen) represents the covering type(say,
current type).
AWS A5.1 Electrode Classifications :
Carbon Steel(Mild Steel) electrodes are made for low strength steel
(say 60000 psi) or for high strength steel(say, 70000 psi)
First & second digit - Electrode Tensile Strength :
Carbon Steel(Mild Steel) electrodes are made for low strength steel(say 60000 psi) or for high strength
By JGC Annamalai
Tensile Strength,
in 1000 psi
Electrode Welding Positions
EXX1X - All position(Flat, Hori, Vert, OH)
EXX2X - Hori & Flat only
EXX3X - Flat position only
EXX4X - Flat, OH, Hori, Vert.Down
Last digit indicates usability of the
electrode, i.e. (1). type of current
and (2). the type of covering. In
some cases, both the third and
fourth digits are significant.
E 60 1 0
Electrode
Fourth Digit Flux Type
0,1 Cellulose
2,3,4,9 Titania
5,6,8 Lime/Low Hydrogen
7 Iron Oxide
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
Coatings, other Names are :
Cellulose Wood Pulp
Rutile Titania, Titanium Oxide
Iron Oxide Red Oxide, Acidic
Low Hydrogen Calcium / Potassium
Carbonates, Lime, Basic
6
DCRP Basemetal -ve;Electrode +ve DCEP Electrode +ve; Basemetal -ve
DCSP Basemetal +ve; Electrode,-ve DCEN Electrode -ve; Basemetal +ve
Polarity,Now
(Reference-Electrode)
Polarity,Before 20years back
(Reference-Basemetal)

By JGC Annamalai
Tensile Strength,
in 1000 psi
E 60 1 0
Electrode
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
Cellulose Wood Pulp
Polarity,Now
(5). Electric Power :
1
2
3
(6). Effect of Welding Electrode : Electric Current (Low-High); Travel Speed (Low-High) & Arc Too Long
Out of position welding(V or OH) should have smaller amount of
slag for faster solidification to hold the liquid metal & smaller
slag needs lower currents . Titania is used for V & OH positions
DC current is useful for welding with small diameter electrodes,
low currents, out of position welding, welding thin material etc. DC
used in SMAW welding with DCEP. DCEP give deeper
penetration and DCEN give higher electrode melting rate.
Welding requires electric power to have arc and to melt the base
metals to join them. Often the electric power is either DC(from
Generator or Rectifier, normally 20V to 70V) or AC(from
Transformer, normally 50V to 100V).
Mostly the Electrode Coating decides the DC or AC power. DC
power is most widely used as desired stable current is available
and used by critical users like Power Plant, Chemical Plants etc.
AC power is used on low quality works like, structurals.
Similarly, Electrode Coating decides the position of welding.
To have consistent good quality, User Specifications always fix
the type of electrode / type of coating to be used on their plant
works.
Most of the cases, the higher the electrode diameter, higher the
deposition rate and faster the job completion. Larger diameter
needs larger current and larger arc voltage.
Typical for Electrodes(Length-Current-Weight):
Welding Electric
Power
Volts Amps Common
Transformer, AC 50 to 90V 125 to 700
Rectifier DC 20 to 90V 125 to 700
Generator DC 20 to 90V 125 to 700
Spot Welding
300 Amps
12000 Amps and above(milli sec)
Electrode
Diameter
(mm)
Length
(mm)
Current
(A)
(Position
F, H)
Current
(A)
(Position
V, OH)
Pcs/ 5Kg
(approx)
E6010
2.50 350 60-90 50-80 ≈258
3.15 350 80-130 80-110 ≈157
4.00 400 150-190 130-170 ≈90
5.00 450 150-190 130-170 ≈80
2.50 350 60-100 60-90 ≈268
3.15 350 80-150 80-110 ≈163
4.00 400 160-200 150-170 ≈96
5.00 400 180-250 --- ≈62
2.50 350 220
3.15 450 143
4.00 450 73
5.00 450 50
E6010
E6013
E7018
180 -230
140 -180
110 -140
60 -90
DCRP
DCSP
P
7

By JGC Annamalai
Tensile Strength,
in 1000 psi
E 60 1 0
Electrode
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
Cellulose Wood Pulp
Polarity,Now
Welding Currents: (Miller Electrode Recommendations)
8

By JGC Annamalai
Tensile Strength,
in 1000 psi
E 60 1 0
Electrode
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
Cellulose Wood Pulp
Polarity,Now
Welding Currents: (AWS A5.1, Recommendations)
AWS Electrode Classification : A5.1
9

By JGC Annamalai
Tensile Strength,
in 1000 psi
E 60 1 0
Electrode
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
0,1 Cellulose
2,3,4,9 Titania
7 Iron Oxide
Cellulose Wood Pulp
Polarity,Now
(7). Comparison of Electrodes per AWS , ISO & Canadian(CSA) Standards :
Arc is initiated, by touching/scratching the charged electrode tip
on the base metal. Arc is common. In DC welding, we use DCEP
(earlier called DCRP). Normally, electrode is the thinnest among
the contact points on the arc. So, electrode melts first. If the
electrode is cellulose, it will start burning and give out smoke
cover.
Low hydrogen electrodes give out smoke cover late and there is
no shielding at the start of the arc and we have porosity at the
starting point. Grinding the starting point is necessary to avoid
porosity on the finished weld.
10

Bare Electrode Welding :
(1).
(2).
(3).
(4).
(5).
(6).
(7).
(8).
Bare (or light coated) Electrodes: A solid metal electrode with no coating other than that incidental to the manucture of
the electrode, or with a light coating. During the 1890's, arc welding was accomplished with bare metal electrodes
Covered(Shielded Arc) Electrode: A metal electrode which has a relatively thick covering material serving the dual
purpose of stabilizing the arc and improving the properties of the weld metal. Around 1927, the covered electrodes were
produced commercially, by extrusion process. With many variations in the formulations of the covering and the amount
of covering on the mild steel core wire, many different classifications of electrodes are produced today.
Covered Electrodes- Development details are found in Chapter-3 and Timeline is found in the Annex-5
Bare Rod Welding: (a). Striking & establishing the arc were difficult. It stuck almost every time
(b). The rod turned red and started to melt above the arc
The arc was not stable and often wandering. The welded surface was
uneven and often found with open porosity and lot of spatters. The welds
were poor in appearance and welds were having low in ductility, low in
fatique and impact resistance.
Oxygen (O2) and Nitrogen (N2) when in contact with molten metal caused
brittle and porous welds, due to the formation of oxides, nitrodes.
Moisture entered the arc and turned into steam created porosity or split into Oxygen and Hydrogen and formed
oxides and nascent hydrogen. Steam was also caused spatters, as propellant.
The melting rate was slow and the work completion is slow, due to thermal losses at electrode & at weld.
Welds were hard due to sudden cooling and cracking also observed on welds.
Hydrogen entered the weld arc and formed nascent hydrogen and these hydrogen atoms were able to travel inside
the metal/weld and stay in the pockets/voids and started increasing the pressure and cracking the metal.
Iron and other alloy elements were burnt in the arc temperature and evaporated and often the critical metal
composition was found appreciably reduced due to metal oxidation and evaporation.
Present Day Electrodes: have flux coatings/coverings. There are more than 100 flux ingredients, available in the market
to make a particular type of electrode. Manufacturer has many electrodes with different Brand Name, each meeting
AWS A5.1, with little changes in formulation. Formulations are secrets and they are protected by patents.
Difficulties
Earlier days, bare electrodes were used to weld/to join metals. The welders experienced difficulties :
(c). Welds oxidized, burned up, lot of spatters (d).Bead - it was the worst weld
Chapter-5 Importance of Flux Covering on SMAW Electrodes
Sulfur and phosphorous in the metal and rod or on the welding surface, would have formed their low melting
sulfides and phosphates and compounds and created problems, during service.
By JGC Annamalai
11
(a)

By JGC Annamalai
Happening at the Typical SMAW Arc Weld (present day) :
Important Functions or Desired Properties of Flux or Ingredients on the Coated Electrodes:
(1).
For several years, cause for above problems were analysed and improvements were made and the result is the
present coated electrodes. The atmospheric air/gases are the main cause for many of the problems and studies were
made to protect the arc from atmospheric gases. Application of Flux(which forms shielding gases like CO2, CO) on
bare electrode was one method of protecting the electrode arc. The following properties are also desired : easy
cleanup, compatible weld strength, impact properties, uniform bead quality and ability to minimize spatter etc. Electrode
total quality should meet the AWS A5.1 and other such Standards
Shielding of the Weld Metal - The most important function of a coating is to shield the weld metal from the oxygen
and nitrogen of the air as it is being transferred across the arc, and while it is in the molten state. This shielding is
necessary to ensure the weld metal will be sound, free of gas pockets, and have the right strength and ductility. At
the high temperatures of the arc, nitrogen and oxygen combine readily with iron to form iron nitrides and iron oxides
that, if present in the weld metal above certain minimum amounts, will cause brittleness and porosity. Nitrogen is
the primary concern since it is difficult to control its effect once it has entered the deposit. Oxygen can be
counteracted by the use of suitable deoxidizers. In order to avoid contamination from the air, the pool of molten
metal must be protected or shielded by gases that exclude the surrounding atmosphere from the arc and the molten
weld metal. This is accomplished by using gas-forming materials in the coating that break down during the welding
operation and produce the gaseous shield. CO2 is normally produced by the flux reaction and shields the weld.
Popular Ingredients: Wood Pulp(cellulose), Titania(TiO 2 ), Lime stone(CaCO 3 )
10
12

By JGC Annamalai
(2).
(3).
(4).
(5).
(6). Welding in Difficult Position - It is the addition of certain ingredients, primarily titanium compounds, in the coating
that makes it possible to weld out-of-position , vertical and overhead. Slag characteristics, primarily slag's surface
tension and freezing point, determine to a large degree the ability of an electrode to be used for out-of-position
work(vertical & overhead positions). Popular Ingredients: Titanium Compounds (TiO 2 . . . .)
Concentration of the Arc Stream - Concentration or direction of the arc stream is attained by having a
coating crater form at the tip of the electrodes. Use of the proper binders assures a good hard coating that will
maintain a crater and give added penetration and better direction to the arc stream. Popular Ingredients:
Potassium Silicate, Potassium Titanate, Mica
Formation of Slag for Fluxing and for protecting the Welded Beads - The function of the slag is (1) to provide
additional protection against atmospheric contamination, (2) to act as a cleaner and absorb impurities that are
floated off and trapped by the slag, (3) to slow the cooling rate of the molten metal to allow the gases to escape.
The slag also controls the contour, uniformity and general appearance of the weld. This is particularly true in fillet
welds. Slag is a insulating material and prevents the heat to flow outside from weld, thus self annealing the weld and
thus forming ductile weld material. Popular Ingredients: Fledspar, Silica, Zircon, Titania
Stabilization of the Arc - A stabilized arc is one that starts easily, burns smoothly even at low amperages, and can
be maintained using either a long or a short arc length. Popular Ingredients: Alkali earth, Titania, Zircon,
Fledspar
Alloying Additions to Weld Metal - A variety of elements such as chromium, nickel, molybdenum, vanadium and
copper can be added to the weld metal by including them in the coating composition. It is often necessary to add
alloys to the coating to balance the expected loss of alloys of the core wire during the welding operation, due to
volatization/vaporization and chemical reaction. Mild steel electrodes require small amounts of carbon, manganese
and silicon in the deposit to give sound welds of the desired strength level. A portion of the carbon and manganese
is derived from the core wire, but it is necessary to supplement it with ferromanganese and in some cases
ferrosilicon additions in the coating. Popular Ingredients: Ferro-Silicon, Ferro-Manganese, Ferroalloys
Flux Name Chemical Formula
Alumina Al2O3 X X
Cellulose (C6H10O5)x X X X
Clays Al2O3.2SiO2.2H2O X X X X X
Dolomite MgO. CaO.(CO2)2 X X X
Feldspar K2O.Al2O3.6SiO2 X X X
Ferro Alloys FeMn, FeSi, FeTi X X X
Flourspar CaF2 X X X
Iron Oxides FeO, Fe2O3, Fe3O4 X X X X X
Iron Powder Fe X X
Lime CaO X X X
Limestone CaCO3 X X X X X
Pigments - - - X
Potassium Silicate K2SiO3.nH2O X X X
Rutile TiO2 X X X X X
Silica SiO2 X X X X
Sodium Oxide NaO X X
Sodium Silicate Na2SiO3.nH2O X X X X
Talcs 3MgO4SiO2.4H2O X X X X X
Zirconia ZrO2 X
Binders
Slipping
(Extrusion)
Agents
Alloy
Agent
Color
of
Coating
Common Flux Ingredients
on SMAW Electrodes
Gaseous
Protection
Deoxidation
Slag
formers
Viscosity
Control
Arc
Stabilizers
Functions of Flux / Ingredients
10
13

By JGC Annamalai
(7).
(8).
(9).
Major Grouping based on the Coatings or the Ingredients
(1).
(2).
Control of Weld Metal Soundness - Porosity or gas pockets in weld metal can be controlled to a large extent
by the coating composition. It is the balance of certain ingredients in the coating that have a special effect on the
presence of gas pockets in the weld metal. The proper balance of these is critical to the soundness that can be
produced. Ferromanganese is probably the most common ingredient used to attain the correctly balanced formula,
where the porosity is avoided. Popular Ingredients: Ferro alloys
Specific Mechanical Properties to the Weld Metal - Specific mechanical properties can be incorporated into the
weld metal by means of the coating. High impact values for low temperature service, high ductility, and increases
in yield and tensile properties can be attained by alloy additions to the coating. Popular Ingredients: Ferro-Nickel
Insulation of the Core Wire - The coating acts as an electrical insulator so that the core wire will not short-circuit
when welding in deep grooves or narrow openings; coatings also serve as a protection/insulator to the welder when
changing electrodes. Popular Ingredients: All. Pure metal powders are electrical conductive. Ferro-alloys are inert
or neutral to electricity. At the welding temperatures, these ferro alloys will disintegrate and the metal will go as solid
solution alloys in the weld.
Slag Formers - These ingredients
are used primarily to give body or
shape to the slag and impart such
properties as slag viscosity, surface
tension, and melting point. Silica
and magnetite are materials of this
type.
Silica, alumina, feldspar, clay,
ironore, rutile, limestone, ilmenite,
magnesite, white and blue
asbestos, fluorspar, mica,
manganese oxide and many other
minerals, as well as some man-
made materials such as potassium
titanate and titanium dioxide are
used as fluxes and slagging
ingredients. They are giving the
holding power to the slag to hold the
liquid metal in vertical and over
position.
Titanates(TiO2) are said to increase the slag viscosity and Fluorides(Flourspar) are said to decrease the slag
viscosity. TiO2 slag is easy to detach. Slag containing Lime and fluorides are difficult to detach/remove
Shielding Gas Formers - Common gas forming materials used are the carbohydrates, hydrates, and carbonates.
Examples would be cellulose (such as wood flock), the carbonates of calcium and magnesium, and chemically
combined water as is found in clay and mica. These materials evolve carbon dioxide (CO2), carbon monoxide (CO),
and water vapor (H2O) at the high temperature of the welding arc. Free moisture is another gas-forming ingredient
that is found particularly in cellulosic type electrodes and is a part of the formulation in amounts of 2%-3%. It has a
marked influence on the arc and is a necessary ingredient in the E6010 type electrode.
Wood flour, wood pulp, refined
cellulose, cotton linters, starch,
sugar and other organic materials
are used to provide a shielding of
reducing gases.
10
14

By JGC Annamalai
(3)
(4).
(5).
(6).
(7).
Arc Stabilizers - Air is not sufficiently conductive to maintain a stable arc, so it becomes necessary to add coating
ingredients that will provide a conductive path for the flow of current. This is particularly true when welding with
alternating current. Stabilizing materials are titanium compounds, potassium compounds, and calcium compounds.
Alloying Elements - Alloying elements such as molybdenum, chromium, nickel, manganese and give specific
mechanical properties to the weld metal.
Deoxidizers : Silicon, Manganese, Aluminum and other elements are metals in ferro alloy forms, added to purify
the weld(Oxygen killing elements).
Plasticizers/Extruding Agent - Coatings are often very granular or sandy, and in order to successfully extrude
these coatings, it is necessary to add lubricating materials, plasticizers, to make the coating flow smoothly under
pressure. Sodium and potassium carbonates, Mica and Talc are often used.
Fluxing Agents: These ingredients are similar to Slag formers and used primarily to give body or shape to
the slag and impart such properties as slag viscosity, surface tension, and melting point.
15

By JGC Annamalai
(8).
Color of Coatings:
The flux ingredients are expected to do the following functions :
(1). Stabilize the Arc; Ionize the arc gap by releasing electrons
(2). Control Arc Resistivity
(3). Provide a gas to shield the arc and prevent excessive atmospheric contamination of the molten filler metal
(4). Provide scavengers, deoxidizers, and fluxing agents to cleanse the weld
(5). Provide a slag protection layer with the proper melting temperature(about 200°C below weld puddle temperature)
to protect the molten metal from the air and improve the mechanical properties, bead shape and surface
cleanliness of the weld metal
(6). Provide a low density slag to quick float on the weld puddle.
(7). Add alloying elements
(8). Refine the weld pool
(9). Provide proper viscosity for out-of-position welding (TiO2 for Vertical and Overhead position welding)
(10). Promote slag detachability
(11). Produce a smooth weld contour with good wetting
(12). Reduce spatter and fume
Killing of oxygen in the weld metal, happens by the addition of ferro alloys
(Ferro silicon, Ferro manganese, Ferro alloys)
Welding rods are mostly from rimmed steel wires, AISI 1010, or
equivalent. They are also called Hot Rods.
Killing of Steel in Steel Mill, is the process of removal of Oxygen from
liquid metal in Steel laddle or furnace. During electrode flux mixing, this is
done by adding Oxygen remover/oxidizers like Ferro-Managanes, Ferro-
Silicon, Ferro-Aluminum and other metals, which will remove the Oxygen
from weld puddle.
Binders - Soluble silicates such as sodium Silicate (DC) and potassium silicates(AC & DC), are used in the
electrode coating as binders. Functions of binders are to form a plastic mass of coating material capable of
being extruded and baked. The final baked coating should be hard so that it will maintain a crater and have
sufficient strength so that it will not spall, crack or chip, at the electrode operating temperatures and during handling
time. Binders are also used to make coating non-flammable and avoid premature decomposition.
MILD STEEL COVERED ELECTRODES & THEIR WELDING ATTRIBUTES
Classificat
ion
Current Arc Penetrati
on
Covering & Slag Iron
Powder
EXX10 DCEP Digging Deep Cellulose 0- 10%
EXXX1 AC or DCEP Digging Deep Cellulose 0
EXXX2 AC or DCEN Medium Medium Titania - sodium 0-10%
EXXX3 AC or DCEN or DCEP Soft Light Soft Light Titania - potassium 0- 10%
EXXX4 AC or DCEN or DCEP Soft Light Titania - iron powder 25-40%
EXXX5 DCEP Medium Medium Low hyd. - sodium 0
EXXX6 AC or DCEP Medium Medium Low hyd. - potassium 0
EXXX8 AC or DCEP Medium Medium Low hyd. - iron powder 25-40%
EXX20 AC or DCEN Medium Medium Iron oxide - sodium 0
EXX22 AC or DCEN or DCEP Medium Medium Iron oxide - sodium 0
EXX24 AC or DCEN or DCEP Soft Light Titania - iron powder 50%
EXX27 AC or DCEN or DCEP Medium Medium Iron oxide- iron powder 50%
EXX28 AC or DCEP Medium Medium Low hyd. - iron powder 50%
EXX48 AC or DCEP Medium Medium Low hyd. - iron powder 25-40%
16

By JGC Annamalai
Electrodes, Larger Classification of Flux (detailed discussion, in Chapter-A5D)
1. Cellulosic Electrodes
2. Rutile Electrodes
3. Acidic Electrodes
4. Basic Electrodes
Covered Electrode Standards:
Carbon Steel Electrodes.
AWS A5.4, Stainless Steel Covered Electrodes : The flux ingredients are mostly based on rutile and basic material.
Basicity Index for welding slag
The flux is said, as acidic, if the BI, is less than 1
Higher the Basic, higher the impact values & lower the
solid-inclusions.Higher the Acidic, higher beed behaviour.
Required-Electrode flux should withstand the heat and
stay with the core rod, during the Temperature rise.
The above formula contains, various flux ingredients and
this formula is used to determine, whether the flux is
acidic or basic or neutral.
The flux is said as neutral, when the BI is equal to 1 to
1.2 and flux is basic if the BI, is above 1.2 or strong
basic, if BI>2.
Cellulose type is listed in A5.5, but normally not used on low alloy steel welding, due to high percentage of
water content. Lime coating is more common.
AWS A5.1, Carbon Steel Covered Electrodes : This chapter is giving detailed info on the flux coating on the
AWS A5.5, Low Alloy Steel Covered Electrodes : The flux ingredients are mostly based on rutile and basic material.
Welding Electrode Heated up, due to Current Flow & Heat from the Arc at the Electrode Tip
Cellulose type is not used on stainless steel welding, due to high percentage of water content. Lime
coating is more common.
Coating consists of high cellulosic content more than 30% and TiO2 up to 20%. These are all position electrodes
and produce deep penetration because of extra heat generated during burning of cellulosic materials. However,
high spatter losses are associated with these electrodes.
Coating consists of TiO2 up to 45% and SiO2 around 20%. These electrodes are widely used for general purpose
work and are called general purpose electrodes.
Coating consists of iron oxide more than 20%. Sometimes it may be up to 40%, other constituents may be TiO2
10% and CaCO3 10%. Such electrodes produce self detaching slag and smooth weld finish and are used normally
in flat position.
Coating consist of CaCO3 around 40% and CaF2 15-20%. These electrodes normally require baking at temperature
of approximately 250°C for 1-2 hrs or as per manufacturer's instructions. Such electrodes produce high quality weld
deposits which has high resistance to cracking. This is because hydrogen is removed from weld metal by the action
of fluorine i.e. forming HF acid as CaF2 generates fluorine on dissociation in the heat of arc. Hydrogen forming
moisture is also controlled by baking and keeping the electrodes at high temperatures.
17

By JGC Annamalai
Computer modeling, for studying & making an effective (AF max, 36%, PF-14, is considered the best in the group)
Compare:
Welding Flux (Before Backing) Welding Flux (After Backing) (Typical)
18

Functions of Flux Covering on SMAW Electrodes)
Chapter-5
By JGC Annamalai
19
(b)

Popular Name Formula Main Function Usage
1 Cellulose C6H10O5 Gas Forming/ Shielding Produces, CO2. Frequently used on cellulose
electrodes;
2 Limestone CaCO3 Gas Forming/ Shielding Produces CO & CO2, during welding; basic slag
3 Wood Flour CnHnOn Gas Forming/ Shielding Produces, CO2.
4 Bauxite Al2O3 Slag Forming Raises melting temperature and increases viscosity
of slag
5 Dolomite Magnesite, CaMg(CO3)2 Slag Forming Used as slag former in steel making, not in electrode
6 Feldspar Alkali Type, KnNanAlSi3O8;
Plagioclases-CaAl2Si2O8
Slag Forming
7 Fluorspar CaF2 Slag Forming Decreases viscosity of molten slag
8 Ilmenite(ilmenite) FeTiO3 Slag Forming Impure Titanium Oxide
9 Magnetite Iron Oxide, Fe3O4 Slag Forming Magnetic Iron Oxide
10 Periclase Magnesium Oxide, MgO Slag Forming Raises melting temperature and increases viscosity
of molten slag
11 Pyrolusite Manganese dioxide, MnO2 Slag Forming
12 Rutile TiO2(10%Fe) Slag Forming Unrefined Titanium Oxide, Mainstay of Rutile
Electrodes
13 Silica Flour Cristobolite, SiO2 Slag Forming Strong acid slag former
14 Wollastonite Calcium Silicate, CaSiO3 Slag Forming
15 Zirconia Zirconium Oxide, ZrO2 Slag Forming Occational
16 Lithium
Carbonate
Li2CO3 Arc Stabilizer Occational
17 Potassium
Oxalate
K2C2O4 Arc Stabilizer Occational
18 Titania TiO2 Arc Stabilizer Frequently used; purified Titanium Oxide
19 Ferroaluminum 85%Al+15%Fe Deoxidizer Strong deoxidizer
20 Ferrosilicon 50%Si+5%Fe Deoxidizer Silicon is deoxidizer & alloying element
21 Ferrotitanium 40%Ti+60%Fe Deoxidizer Strong deoxidizer & grain-refining agent
22 Zirconium Alloy 40%Zr+40%Si+20%Fe Deoxidizer Deoxidizer
23 Chromium metal Cr=100% Alloying Alloying
24 Elecro-
manganese
Mn=100% Alloying Most common alloying element
25 Electro-Nickel Ni=100% Alloying Alloying
26 Ferromanganese Mn=80%Mn+20%Fe Alloying Alloying
27 Barium Fluoride BaF2 Fluxing Agent
28 Cryolite Na3AlF6 Fluxing Agent Strong fluxing agent
29 Fluorspar CaF2 Fluxing Agent Strong fluxing agent
30 Lithium Chloride LiCl Fluxing Agent Occational
31 Lithium Fluoride LiF Fluxing Agent Very effective flux
32 Witherite BaCO3 Fluxing Agent Produces CO & CO2, during welding; basic slag
33 Bentonite Clay Montmorillonite,
Al2Si4O10(OH)2
Slipping/ Extrusion
Agent
Used, water can be tolerated
34 Glycerin Glycerol, C3H5(OH)3 Slipping/ Extrusion
Agent
Trihydric alcohol
35 Kaolin Clay Kaolinite, Al2Si2O5(OH) Slipping/ Extrusion
Agent
36 Mica Muscovite, KAl2(Si3Al)O10(OH)2 Slipping/ Extrusion
Agent
37 Talc Soapstone, Mg3Si4O10(OH)2 Slipping/ Extrusion
Agent
38 Asbestos Cristotile, Mg3Si2O5(OH)4 Binders Improves, durability of the covering
39 Dextrin Starch, C6H10O5 Binders
40 Gum Arabic Acacia, CnOnHn Binders
41 Potassium
Silicate
K2OnSiO2(OH)n Binders For AC use
42 Sodium Silicate Water Glass, Na2OnSiO2(OH)n Binders Most Frequently used
43 Sugar Sugar, Cn(OH)n Binders
Short List of Welding Electrode Flux-Ingredients
Chapter-5
20
(c)

Weld metal will have, same Chemical composition, but they have :
(a). Different Coatings, (b). Welding Properties, (c). WeldingSpeeds, and (d). Weld Metal Quality.
(1). Cellulose Electrodes
(2) Rutile Electrodes
(3). Basic Electrodes
Unalloyed basic electrodes give moderate welding speed in the flat position but are faster than other types when
welding vertically upwards. The reason for this is that basic electrodes can be deposited at a higher current in the
vertical position than other types of electrode. In addition, the amount of weld metal deposited per electrode is greater
than that of other electrodes which can be used in this position. This results in a smaller number of electrode
changes. The normal result is therefore a higher fusion rate and higher arctime factor when welding vertically
upwards with basic electrodes compared with other types.
The slag from basic electrodes is normally not easy to remove compared to the slag from acid or rutile electrodes.
But, in spite of this, it can be classed as easily detachable. The slag from basic electrodes has a lower melting point,
compared the weld metal(start to float fast) than that from rutile or acid electrodes. The risk of slag inclusions during
normal production welding is therefore unusually small when basic electrodes are used, even if the slag is not
completely removed between beads during multi-run welding.
The weld metal from basic electrodes has a low hydrogen content and usually has good toughness even at low
temperatures. Basic electrodes are less likely to produce either hot cracks or cold cracks compared with other types
of electrode. The superiority of basic electrodes from this point of view are well established when manganese alloyed
structural steels, pressure-vessel steels and ship's plate with a nominal tensile strength of 490-530 MPa (71000-
77000 psi, 50-54 kg/mm2) are welded.
Rutile electrodes generally produce a higher welding speed, which increases as the weld metal recovery increases,
up to a maximum of about 140 g/minute for 6mm diameter.
They are all easy to use, produce excellent slag detachability, fine bead appearance and are particularly suitable for
welding horizontal/vertical fillets. The weld metal has tensile properties which are as high as, or somewhat higher
than, those of the weld metal from unalloyed basic electrodes but have lower elongation and impact strength.
The evenness of the weld and the smooth transition of the base material make joints produced with rutile electrodes
at least as good in terms of fatigue strength as unmachined joints produced using basic electrodes. Unalloyed rutile
electrodes, irrespective of their efficiency, can be recommended for welding mild steel with a nominal tensile strength
of 440 MPa (64000 psi, 45 kg/mm
2
). When it comes to the tensile strength of the deposit, rutile electrodes can also
be used for welding steels with a nominal tensile strength of more than 440 MPa (64000 psi, 45 kg/mm
2
)
High strength Steels, General rule : Only electrodes producing a weld metal with a low hydrogen content, e.g. basic,
rutile basic or zircon-basic electrodes, should be used to weld these steels (440 MPa, 64000 psi, 45 kg/mm
2
).
For each steel grade(CS, LAS, SS), there are often a large number of electrode types to choose from, all of which
produce similar weld metal compositions. This large choice makes it possible to choose the electrode which produces
the right weld metal quality at the lowest cost.
Cellulose electrodes are easy to use in all welding positions and are particularly good for vertical and overhead
welding. Cellulose electrodes are recommended for all positional welding where the mechanical properties of the
deposit are of the greatest importance and radiographic requirements must be met.
Vertical and overhead welding often require an electrode one size larger in comparison to electrodes with other types
of coating. Cellulose electrodes are extremely good for vertical-down welding. Higher tensile steel requires preheating
and higher inter-pass temperatures than when the welding is done with low-hydrogen electrodes.
Suitable Electrode Flux for SMAW Electrodes
Chapter-5
By JGC Annamalai
21
(d)

Suitable Electrode Flux for SMAW Electrodes
Chapter-5
By JGC Annamalai
21
(4) Acidic Electrodes
Acid electrodes without iron powder in the covering are easier to strike than basic electrodes but more difficult to
strike and re-strike than rutile electrodes. The welding speed is moderate. The weld beads are smooth and shiny. The
slag is inflated and easy to remove. The weld metal has a lower yield stress and tensile strength compared with that
produced by rutile electrodes, but it has higher elongation and impact strength.
Earlier, these electrodes dominated the market. Now Acid Electrodes are gradually replaced by rutile electrodes for
welding in the flat position and basic electrodes for horizontal, vertical and overhead positional welding. Unalloyed
acid electrodes are suitable for welding steels with a nominal tensile strength max. 440 MPa (64000 psi, 45 kg/mm2).
The higher the hardenability of the steel to be welded, the greater the necessity to use basic electrodes
and the greater the need for low moisture content in the coating.
22

(1). AWS gives only General Group Covering. Various Flux / Ingredients and thier percentages are not given.
(2). How the Electrode is made.
4 Typical Tables(with flux ingredients and their percentage) are attached.
Table-1, gives % flux for 3 electrodes. They are the more popular electrodes in the Industry.
Table-2, gives % of Flux for 5 Electrodes.
Table-3, gives % of Flux for 8 Electrodes.
Table-4, gives % Flux for 10 Electrodes.
AWS D5.1, and the flux or covering typess
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
The present AWS A5.1 list has about 18 Electrodes. Many of electrodes, are in the same group but with little variations, in
key ingredients. Many of the New electrodes are Iron Oxide Electrodes. There are over 100 electrodes, made by the
manufacturers and the manufacturers say,the electrodes meet AWS A5.1. There are also many patents. Several
electrodes, in the group, will have same composition, but with little changes, in specific Ingredients. (It is similar to mummy
making a Curry. Salt, Chilly/Pepper, Sour/lime are main additions to the curry. But, we will find the Curry taste and flavour
differ, mummy to mummy. It is unique to each mummy).
AWS D5.1 requirement on Flux:
AWS has specification to control "all weld metal" and not on flux ingredients or on their percentages. AWS has required
weld metal chamical analysis, various mechanical and metallurgical tests. (Brief AWS requirement is listed in Chapter - 8.
Tables 1 to 4 are prepared from different sources. We see the % ingredients differ, appreciably.
This chapter gives, % of Flux(Ingredients) on the SMAW Electrodes
AWS does not say on
Chapter-6 Flux Coating (Typical %) on the Covered Electrodes - AWS-SMAW
23

Chapter-6
Flux Ingredients Formula Function E6010 E6012 E6020 E7015 E7018
Cellulose C6H10O5 Gas Forming/ Shielding 25 5
Limestone CaCO3 Gas Forming/ Shielding 40 30
Fluorspar CaAl2Si2O8 Slag Forming 15 10
Rutile TiO2(10%Fe) Slag Forming 55 20
Titania TiO2 Arc Stabilizer 12
Asbestos(max)
Cristotile,
Mg3Si2O5(OH)4
Binders
15 10 15 10 8
Iron Oxide FeO, Fe2O3, Fe3O4 Iron Addition 1 30
Clay
Al2Si2O5(OH),
Al2Si4O10(OH)2
Slipping/Extrusion
Agent
10 5 5 2
Iron Powder Fe Adding Fe 25
Ferrosilicon 50%Si+50%Fe Deoxidizer 2 2 2 5 5
Ferromanganese 80%Mn+20%Fe Deoxidizer 4 4 6 4 4
Solium Silicate(max) Na2OnSiO2(OH) Binders(DC) 40 25 30 25
Potassium Silicate(max)K2OnSiO2(OH)n Binders(AC,DC) 25
Chemical Composition, by Weight (% after Baking)
E6010 E6012 E6020 E7015 E7018
CaO 25.5 14.4
TiO2 10.1 46 15.4
CaF2 15.2 11
SiO2 47 23.6 40 20 20.5
Al2O3 5 2.3 2.8 2
MgO 3.2 2 2.8 1.2 2
Na3AlF3 5.7 5
FeO 1.3 7 30.7
Na2O 5.1 2.4 3.3 1.7
K2O 1.2
Si 1.5 1.5 1 2.8 2.5
Mn 2.8 2.5 4 2 1.8
Fe 2.8 28.5
CO and CO2 20.2 12
Volatile Matter 25 5
Moisture 4 2 0.54 0.1 0.1
100 97 100.04 100 101
8 Electrodes
Table - 3
5 Electrodes Table - 1
Flux Covering on SMAW Electrodes, by weight %, before Baking
24
(c)

COATING
CONSTITUENT
PRIMARY SECONDARY E6010,
E6011
E6013 E7018
E7024
E7028
CELLULOSE SHIELDING GAS . . . 25-40 2-12 . . . 1-5 . . .
CALCIUM CARBONATE SHIELDING GAS FLUXING AGENT . . . 0-5 15-30 0-5 0-5
FLUORSPAR SLAG FORMER FLUXING AGENT . . . . . . 15-30 . . . 5-10
DOLOMITE SHIELDING GAS FLUXING AGENT . . . . . . . . . . . . 5-10
TITANIUM DIOXIDE (RUTILE) SLAG FORMER ARC STABILIZER 10-20 30-55 0-5 20-35 10-20
POTASSIUM TITANATE ARC STABILIZER SLAG FORMER (A) (A) 0-5 . . . 0-5
FELDSPAR SLAG FORMER STABILIZER . . . 0-20 0-5 . . . 0-5
MICA EXTRUSION STABILIZER . . . 0-15 . . . 0-15 . . .
CLAY EXTRUSION SLAG FORMER . . . 0-10 . . . . . . . . .
SILICA SLAG FORMER . . . . . . . . . . . . . . . . . .
ASBESTOS SLAG FORMER EXTRUSION 10-20 . . . . . . . . . . . .
MANGANESE OXIDE SLAG FORMER ALLOYING . . . . . . . . . . . . . . .
IRON OXIDE SLAG FORMER . . . . . . . . . . . . . . .
IRON POWDER DEPOSITION RATE CONTACT WELDING . . . . . . 25-40 40-55 40-55
FERROSILICON DEOXIDIZER . . . . . . . . . 5-10 0-5 2-6
FERROMANGANESE ALLOYING DEOXIDIZER 5-10 5-10 2-6 5-10 2-6
SODIUM SILICATE BINDER FLUXING AGENT 20-30 5-10 0-5 0-10 0-5
POTASSIUM SILICATE ARC STABILIZER BINDER (B) 5-15(B) 5-10 0-10 0-5
(A) REPLACES TITANIUM DIOXIDE (RUTILE) TO PERMIT USE WITH ALTERNATING CURRENT.
(B) REPLACES SODIUM SILICATE TO PERMIT USE WITH ALTERNATING CURRENT
TYPICAL FUNCTIONS AND COMPOSITIONS OF CONSTITUENTS FOR SELECTED
M.S. SMAW ELECTRODE COATINGS (ASM Vol-6)
COMPOSITION RANGE OF COATING
ON ELECTRODE
FUNCTION OF CONSTITUENT
Chapter-6 Table-4
25
(e)

Electrode Flux Covering Formula % Function Shielding Characteristics Uses / Applications
Cellulose C6H10O5 35% Gas Former 40% H2
Titania TiO2 15% Slag Former -Arc Stabilizer 40% CO + CO2
Ferromanganese Fe-Mn 5% Deoxidizer -Alloying 20% H2O
Talc Mg3Si4O10(OH)2 15% Slag Former
Sodium Silicate Na2SiO3 25% Binder -Fluxing Agent
Moisture H2O 5%
Calcium Carbonate CaCO3 5% Shielding Gas
Cellulose C6H10O5 10% Shielding Gas 40% H2
Fledspar Complex Silicates 15% Slag Former
Titania TiO2 20% Slag Former 40% CO + CO2
Talc Mg3Si4O10(OH)2 8% Extrusion
Zircon ZrSiO4 14% Slag Former
Ferromanganese Fe-Mn 6% Alloying 20% H2O
Potassium Silicate K2SiO3 20% Binder 20% CO2
Moisture H2O 2%
Calcium Carbonate CaCO3 30% Gas Former -Fluxing Agent
Fluorspar CaF2 20% Slag Former -Fluxing Agent
Ferromanganese Fe-Mn 5% Deoxidizer -Alloying 80% CO
Iron Powder Fe 30% Deposition Stabilizer
Potassium Silicate K2SiO3 15% Binder -Arc Stabilizer 20% CO2
Moisture H2O 0.1%
Note:
Titania Electrodes are also called Rutile Electrodes or Titanium Oxide Electrodes
Low Hydrogen Electrodes are also called Lime Stone Electrodes or Lime Electrodes or Basic Electrodes
E7018
(Low
Hydrogen)
The main advantages of basic
electrodes are the outstanding
toughness properties of the
weld metal and its resistance to
hot and cold cracks. Basic-
coated electrodes have a
coarse droplet material transfer,
can be used to weld in all
positions and have somewhat
coarsely rippled seams. The
slag can be relatively easily
removed, but not as easily as
with rutile-coated electrodes.
Used in critical areas where
"Quality is First", Nuclear
and other fossil power
plants, Oil & Gas, Refinery,
Chemical Plants, oil
Platforms, Large Bridges,
Large Cranes & earth
movers etc.
Three Very Popular Electrodes
Importance of Welding Electrode Flux (related AWS A5.1)
E6010
(Cellulose)
Due to the high level of
cellulose in the coating, they
have excellent properties for
out-of-position welding, but not
good for horizontal welding.
They are therefore mainly used
for vertical-down welding on
large pipes.
Mostly used in Cross
Country pipelines and at
joints where joint
penetration is essential.
E6013
(Titania)
These electrodes are very
popular due to their good
welding properties. The welding
arc is stable and calm and is
easy to reignite, the seams are
finely rippled, and most of the
slag comes off by itself.
Rutile-coated electrodes have
sufficient toughness properties,
but are only suitable for out-of-
position welding to a limited
extent (high-alloy).
Mostly used on Structures.
Most of the middle and
small size fabricaiton
Shops use it. Very popular
among welders as it gives
quick start, stable arc, self
peeling slag and user
friendly . Generally RT is
ok. These electrodes are
the largest used among the
electrodes.
Fluxes and their % proportions
Table-3
By JGC Annamalai
Chapter-6
26
(b)

Table-4
E6010 E6011 E6012 E6013 E6020 E6027 E7014 E7018 E7024 E7028
DCEP
AC or
DCEP
AC or
DCEN
AC, DCEP,
or DCEN
AC or
DCEN
AC or
DCEN
AC,
DCEP, or
DCEN
AC or DCEP
AC,
DCEP, or
DCEN
AC or
DCEP
Function,
Primary Use
Function,
Secondary Use
Cellulose
(Sodium)
Cellulose
(potassium)
Titania
(Sodium)
Titania
(Potassium)
Iron
Oxide
Iron Oxide
/ Iron
Powder
Titania
(iron
powder)
Lime, Iron Powder
(also called Low
H2)
Titania,
Iron
Powder
Lime,
Iron
powder
Calcium Carbonates CaCO3(Calcite) Shielding Gas Fluxing Agent 1 3 2.7 2.6 4.9 36.4 13.1
Cellulose C6H10O5 Shielding Gas Fluxing Agent 21 15 4 12 2.6 1 10 1
Dolamite CaMg(CO3)2 Shielding Gas Fluxing Agent 4.6
Alumina Al2O3 Slag Former - 2.7
Iron Oxide FeO, FeO2, Fe3O4 Slag Former - 26.2 16.5
Magnesium Oxide MgO Slag Former - 1.3
Silica SiO2 Slag Former - 1.6 2.6 16 4 2.7
Manganese di Oxide MnO, Mn2O3, Mn3O4 Slag Former Alloying 6.9
Fledspar KAlSi3O8–NaAlSi3O8–CaAl2Si2O8 Slag Former Arc Stabilizer 10 14.3 16 14 8.2
Titanium Oxide TiO2 Slag Former Arc Stabilizer 10.5 40 10.3 8.6 22 3.6 22 10
Zircon ZrSiO4 Slag Former Arc Stabilizer 13.8 2.7 3
Zirconia ZrO2 Slag Former Arc Stabilizer 6.6
Asbestos Complex Silicates Slag Former Extrusion 10.5 8
Potassium Silicate K2SiO3 Arc Stabilizer Binder 18.6 13.8 16.6 7 18
Potassium Titanate K2Ti O3 Arc Stabilizer Slag Former 18.9 12.3
Ferro-manganese Fe-Mn Alloying Deoxidiser 5.3 5.3 8 5.6 10.3 10.8 4.6 5.4 5
Iron Powder Fe Decompotion Iron% Increase 32.4 19.7 27.4 39 45
Ferro-silicon Fe-Si Deoxidiser - 4.3 1.8 4.4
Glycerin C3H8O3 Extrusion - 1.1 0.7
Mica Complex Silicates Extrusion Arc Stabilizer 6.6
Talc Mg3Si4O10(OH)2 Extrusion Binder 8.3 10 7.7
Clay Oxides of Si, Al, Mg Extrusion Slag Former 3.9 3.3
Sodium Silicate (Na2O)X·SiO2 Binder Fluxing Agent 52.7 36.7 25 30 18 7
Total, % 100 100 100 100 100 100 100 100 100 100
(b). Electrode Fabricator, through their licence and/or experience , establishes the optimum % of Flux coating for the Electrode Function. Typical sample is given above. % Composition depends on Purity.
AWS Classifications (the latest AWS A5.1 has about 18 electrodes)
Chemicals present in
the electrode flux
(mostly minerals / ores
from earth)
Chemical Formula
Current Type
Chapter-6 Flux Coating(%) on the Covered Electrodes - AWS -SMAW , (10 Electrodes)
Notes:
(a).AWS A5.1- Though AWS indicate major flux type/group , it does not specify what chemicals are to be used as flux and their %. The above
Table contains 10 electrode types and it was prepared, for old AWS A5.1. Present AWS A5.1 contains, about 18 electrodes. Their electrode
chemistry are expected same, for the group in the Table.
(c). Minerals : They are mostly Rocks/Ores.
(1). Alumina - It is aluminum oxide , a chemical compound of aluminium and oxygen with the chemical formula Al2O3;
(2). Dolamite - Dolomite is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally CaMg(CO3)2.
(3). Fledspar-Feldspars (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8) are a group of rock-forming tectosilicate minerals that make up about 41% of the Earth's continental crust by weight;
(4). Mica-Mica is a group of sheet silicate minerals; (7). Rutile or Titania or Titanium Oxide(TiO2) is a mineral composed primarily of titanium dioxide (TiO2)
(5). Silica-is sand(SiO2); (8). Talc-a white, grey, or pale green soft mineral with a greasy feel, occurring as translucent masses or laminae and consisting of hydrated magnesium
silicate.;
(6). Zirconia(ZrO2) is the ore and Zircon is Element.
Flux Groupings
By JGC Annamalai
E7048
Low Hydrogen(Lime)
E6018
E7015
E7016
E7018
E7018M
E7028
E7027
HighIron Oxide
E6020
E6022
E6027
Titania
E6012
E6013
E6019
E7014
E7024
E6010
E6011
Cellulose
27
(d)

More often the larger sizes are used in
the flat and horizontal welding positions
rather than in the vertical and overhead
welding positions. The larger sizes are
often used for single pass, high-speed,
high current fillet welds in the
horizontal welding position. Their ease
of handling, good fillet weld face, and
ability to bridge wide root openings
under conditions of poor fit, and to
withstand high amperages make them
very well suited to this type of work
Weld metal from these electrodes is
generally lower in ductility and may be
higher in yield strength (1 ksi to 2 ksi
[0.7 MPa to 1.4 MPa]) than weld metal
from the same size of either the E6010
[E4310] or E6011 [E4311] electrodes
Fillet welds tend to have a convex
weld face with smooth even
ripples in the horizontal welding
position, and widely spaced
rougher ripples in the vertical
welding position which become
smoother and more uniform as
the size of the weld is increased.
Ordinarily, a larger size fillet must
be made in the vertical and
overhead welding positions using
E6012 [E4312] electrodes
compared to welds with E6010
[E4310] and E6011 [E4311]
electrodes of the same diameter.
Electrodes are characterized by low penetrating arc and dense slag,
which completely covers the bead. This may result in incomplete root
penetration in fillet welded joints. The coverings are high in titania,
usually exceeding 35 percent by weight, and usually are referred to as
the “titania” or “rutile” type. The coverings generally also contain
small amounts of cellulose and ferromanganese, and various siliceous
materials such as feldspar and clay with sodium silicate as a binder.
Also, small amounts of certain calcium compounds may be used to
produce satisfactory arc characteristics on dcen (electrode negative).
The E6012 [E4312]
electrodes are all-position
electrodes and usually are
suitable for welding in the
vertical welding position
with either the upward or
downward progression. .
The electrode size used for
vertical and overhead
position welding is
frequently one size smaller
than would be used with an
E6010 [E4310] or E6011
[E4311] electrode
AWS
Electrode
Class
Selection of Welding Electrodes
Electrical
(Polarity, Amps & Voltage)
Electrode Applications
Welding Positions
Weld Bead Shapes
Coating - Arc - Slag
E6012
[E4312]
Electrodes are characterized by a deeply penetrating, forceful, spray
type arc and readily removable, thin, friable slag which may not seem
to completely cover the weld bead. The coverings are high in
cellulose, usually exceeding 30 percent by weight. The other materials
generally used in the covering include titanium dioxide, metallic
deoxidizers such as ferromanganese, various types of magnesium or
aluminum silicates, and liquid sodium silicate as a binder. Because of
their covering composition, these electrodes are generally described
as the high-cellulose sodium type.
These electrodes are
recommended for all
welding positions,
particularly on multiple
pass applications in the
vertical and overhead
welding positions and
where welds of good
soundness are required.
They frequently are
selected for joining pipe
and generally are capable
of welding in the vertical
position with either uphill or
downhill progression.
The majority of applications for these
electrodes is in joining carbon steel.
However, they have been used to
advantage on galvanized steel and on
some low alloy steels. Typical
applications include shipbuilding,
buildings, bridges, storage tanks,
piping, and pressure vessel fittings.
Since the applications are so
widespread, a discussion of each is
impractical. Sizes larger than 3/16 in
[5.0 mm] generally have limited use in
other than flat or horizontal-fillet
welding positions.
These electrodes have
been designed for use
with dcep (electrode positive).
The maximum amperage that
can generally be used with the
larger sizes of these electrodes
is limited in comparison to that
for other classifications due to
the high spatter loss that occurs
with high amperage.
E6010
[E4310]
E6011
[E4311]
The electrodes duplicate the usability characteristics and mechanical
properties of the E6010 [E4310] classification. Arc action, slag, and
fillet weld appearance are similar to those of the E6010 [E4310]
electrodes.
The coverings are also high in cellulose and are described as the
high-cellulose potassium type. In addition to the other ingredients
normally found in E6010 [E4310] coverings, small quantities of
calcium and potassium compounds usually are present.
Sizes larger than 3/16 in
[5.0 mm] generally have
limited use in other than
flat or horizontal-fillet
welding positions.
Normally, similar to E6010 Electrodes are designed to be
used with ac current . Although
also usable with dcep (electrode
positive), a decrease in joint
penetration will be noted when
compared to the E6010 [E4310]
electrodes.
Fillet welds usually have a
relatively flat weld face and have a
rather coarse, unevenly spaced
ripple.
Fillet welds usually have a
relatively flat weld face and have a
rather coarse, unevenly spaced
ripple.
By JGC Annamalai
Chapter-7
28

AWS
Electrode
Class
Electrical
Welding Positions
Weld Bead Shapes
By JGC Annamalai
Chapter-7
A7.6 Low-Hydrogen Electrodes
A7.6.1 Electrodes of the low-hydrogen classifications E6018 [E4318], E7015 [E4915], E7016 [E4916], E7018
[E4918], E7018M [E4918M], E7028 [E4928], and E7048 [E4948]) are made with inorganic coverings that contain minimal moisture. The covering moisture test such as specified in AWS A4.4M, Standard
Procedure for Determination of Moisture Content of Welding Fluxes and Welding Electrode Flux Coverings, converts hydrogen-
bearing compounds in any form in the covering into water vapor that is collected and measured. The test thus assesses the potential hydrogen available from an electrode covering. All low-hydrogen
electrodes, in the as manufactured condition or after conditioning, are expected to meet a maximum covering moisture limit of 0.6 percent or less, as required in Table 10.
A7.6.3 In order to maintain low-hydrogen electrodes with minimal moisture in their coverings, these electrodes
should be stored and handled with considerable care. Electrodes which have been exposed to humidity may absorb considerable moisture and their low-hydrogen character may be lost. Then conditioning can
restore their low-hydrogen character (see Table A3.). Reconditioning is done at 350 °C for min. 1 hour. Electrodes can be reconditioned, max. 5 times.
General
Low
Hydrogen
Electrodes
E6018 ,
E7015 ,
E7016
E7018 ,
E7018M ,
E7028 ,
E7048
E6013
[E4313]
E7014
[E4914]
Electrodes contain rutile, cellulose, ferromanganese, potassium
silicate as a binder, and other siliceous materials. The potassium
compounds permit the electrodes to operate with ac at low amperages
and low open-circuit voltages. A7.4.3 E6013 [E4313] electrodes are
similar to the E6012 [E4312] electrodes in usability characteristics and
bead appearance. . The usability characteristics of E6013 [E4313]
electrodes vary slightly from brand to brand. E6013 [E4313]
electrodes, although very similar to the E6012 [E4312] electrodes,
have distinct differences. Their flux covering makes slag removal
easier and gives a smoother arc transfer than E6012 [E4312]
electrodes. This is particularly the case for the small diameters 1/16
in, 5/64 in, and 3/32 in [1.6 mm, 2.0 mm, and 2.5 mm]. However, the
larger diameters are used on many of the same applications as E6012
[E4312] electrodes and provide low penetrating arc. The smaller
diameters provide a less penetrating arc than is obtained with E6012
[E4312] electrodes.
In addition, the weld metal is definitely freer of slag and oxide
inclusions than E6012 [E4312] weld metal and exhibits better
soundness
Their flux covering makes slag removal easier and gives a smoother
arc transfer than E6012 [E4312] electrodes.
Recommended for sheet metal
applications where their ability to weld
satisfactorily in the vertical welding
position with downward progression is
an advantage. This is particularly the
case for the small diameters 1/16 in,
5/64 in, and 3/32 in [1.6 mm, 2.0 mm,
and 2.5 mm]. This permits satisfactory
operation with lower open-circuit ac
voltage. E6013 [E4313] electrodes
were designed specifically for light
sheet metal work.
E6013 [E4313]
electrodes usually
cannot withstand the high
amperages that can be used with
E6012 [E4312] electrodes in the
flat and horizontal welding
positions. Amperages in the
vertical and overhead positions,
however, are similar to those
used with E6012 [E4312]
electrodes.
A7.6.4 Low-hydrogen electrode coverings can be designed to resist moisture absorption for a considerable time in a humid environment. The absorbed moisture test (see Section 17) assesses this
characteristic by determining the covering moisture after nine hours exposure to 80°F [27°C], 80 percent relative humidity air. If, after this exposure, the covering moisture does not exceed 0.4 percent,
then the optional supplemental designator, “R,” may be added to the electrode classification designation, as specified in Table 10. See also A9.3 in this Annex.
A7.6.2 The relative potential of an electrode to contribute to diffusible hydrogen in the weld metal can be assessed more directly, but less conveniently, by the diffusible hydrogen test, as specified in Section
18. The results of this test, using electrodes in the as-manufactured condition or after conditioning, permit the addition of an optional supplemental diffusible hydrogen designator to the classification
designation according to Table 11 (see also A9.2 in this Annex).
Typical weld beads are smooth
with fine ripples. Joint penetration
is approximately the same as that
obtained with E6012 [E4312]
electrodes, which is advantageous
when welding over a wide root
opening due to poor fit up. The
face of fillet welds tends to be flat
to slightly convex.
Electrode coverings are similar to those of E6012 [E4312] and E6013
[E4313] electrodes, but with the addition of iron powder for obtaining
higher deposition efficiency. The covering thickness and the amount
of iron powder in E7014 [E4914] are less than in E7024 [E4924]
electrodes. The slag is easy to remove. In many cases, it removes
itself.
The amount and character
of the slag permit E7014
[E4914] electrodes to be
used in all positions
The iron powder also permits the
use of higher amperages than
are used for E6012 [E4312] and
The arc action tends to be quieter
and the bead surface smoother
with a finer ripple. With a more
fluid slag, are used for horizontal
fillet welds and other general
purpose welding. These
electrodes produce a flat fillet
weld face rather than the convex
weld face characteristic of E6012
[E4312] electrodes. They are also
suitable for making groove welds
because of their concave weld
face and easily removable slag.
29

AWS
Electrode
Class
Electrical
Welding Positions
Weld Bead Shapes
By JGC Annamalai
Chapter-7
E7018
(E4918)
E7018 [E4918] electrode coverings are similar to E7015 [E4915]
coverings, except for the addition of a relatively high percentage of
iron powder. The coverings on these electrodes are slightly thicker
than
those of the E7016 [E4916] electrodes. As is common with all low-
hydrogen electrodes, a short arc length should be maintained at all
times.
The electrodes
are characterized by a smooth,
quiet arc, very low spatter, and
medium arc penetration. E7018
[E4918] electrodes can be used at
high travel speeds.
The fillet welds made in the
horizontal and flat welding
positions have a slightly
convex weld face, with a
smooth and finely rippled
surface.
The fillet welds made in the horizontal
and flat welding positions have a
slightly convex weld face, with a
smooth and finely rippled surface.
E6018 [E4318] electrodes possess
operating and mechanical property
characteristics similar to E7018
[E4918] except at a lower strength
level.
E7018 [E4918] low-hydrogen
electrodes can be used with
either ac or dcep.
E7048
[E4948]
Electrodes of the E7048 [E4948] classification have the same
usability, composition, and design characteristics as E7018 [E4918]
electrodes,
are specifically designed
for exceptionally good
vertical welding with
downward progression
E7028
[E4928]
The E7028 [E4928] electrode coverings are much thicker. They make
up approximately 50 percent of the weight of the electrodes. The iron
content of E7028 [E4928] electrodes is higher (approximately 50
percent of the weight of the coverings). Consequently, on fillet welds
in the horizontal position and groove welds in the flat welding position,
E7028 [E4928] electrodes give a higher deposition rate than the
E7018
[E4918] electrodes for a given size of electrode.
are suitable for fillet welds
in the horizontal welding
position and groove welds
in the flat welding position
only, whereas E7018
[E4918] electrodes are
suitable for all positions.
On works, requiring, high rate of low
hydrogen weld deposits .
E7018M [E4918M] is intended to
be used with dcep type current in
order to produce the optimum
mechanical properties.
The Arc of electrodes is moderately penetrating. The slag is heavy,
friable, and easy to remove. Electrodes are commonly used for
making small welds on thick base metal, since the welds are less
susceptible to cracking. The shortest possible arc length should be
maintained for best results with E7015 [E4915] electrodes. This
reduces the risk of porosity. The necessity for preheating is reduced;
therefore, better welding conditions are provided.
Electrodes up to and
including the 5/32 in [4.0
mm] size are used in all
welding positions. Larger
electrodes are used for
groove welds in the flat
welding position and fillet
welds in the horizontal and
flat welding positions.
EThey are also used for welding high-
sulfur and enameling steels. Welds
made with E7015 [E4915] electrodes
on high-sulfur steels may produce a
very tight slag and a very rough or
irregular bead appearance in
comparison to welds with the same
electrodes in steels of normal sulfur
content.
Electrodes are
low-hydrogen electrodes
to be used with dcep (electrode
positive). The
slag is chemically basic.
Amperages for E7015 [E4915]
electrodes are higher than those
used with E6010 [E4310]
electrodes of the same diameter.
The weld face is convex, although
a fillet weld face may be flat.
Fillet welds made in the horizontal
and flat welding positions have a
slightly convex weld face, with a
smooth and finely rippled surface.
E7018M
[E4918M]
E7018M [E4918M] electrodes are similar to E7018-1H4R [E4918-
1H4R] electrodes, except that the testing for mechanical properties
and for classification is done on a groove weld that has a 60 degree
inapplies
equally well to the E7016 [E4916] electrodes. The electrodes are
characterized by a smooth, quiet arc, very low spatter, and medium
arc penetration.
E7015
[E4915]
E7016
(E4916)
All similar to E7015
Characteristics similar to E7015. It will work also on AC. Binder is
Potassium silicate and contains Potassium salts.
30

AWS
Electrode
Class
Electrical
Welding Positions
Weld Bead Shapes
By JGC Annamalai
Chapter-7
The E7024 [E4924]
electrodes are well suited
for making fillet welds in
the flat or horizontal
position
E7027
[E4927]
E7027 [E4927] electrodes have the same usability and design
characteristics as E6027 [E4327] electrodes
These electrodes are intended for use
in situations requiring slightly higher
tensile and yield strengths than are
obtained with E6027 [E4327]
electrodes
Electrodes of these
classifications can be operated
on ac, dcep, or dcen.
E6027
[E4327]
E6027 [E4327] electrode coverings contain large amounts of iron
powder in combination with ingredients similar to those found in
E6020 [E4320] electrodes. The coverings on E6027 [E4327]
electrodes are
also very thick and usually amount to about 50 percent of the weight
of the electrode. E6027 [E4327] electrodes have a spray-type arc.
They will operate at high travel speeds. Arc penetration is medium.
Spatter loss is very low. E6027 [E4327] electrodes produce a heavy
slag which is honeycombed on the underside. The slag is friable and
easily removed
Welds produced with E6027
[E4327] electrodes have a flat to
slightly concave weld face with a
smooth, fine, even ripple, and
good wetting along the sides of
the joint.
Electrodes will produce a
flat or slightly concave weld
face on fillet welds in the
horizontal position
with either ac or dcen.
The weld metal may be slightly inferior
in radiographic soundness to that from
E6020 [E4320]
electrodes.
The E6027 [E4327] electrodes
are designed for fillet or groove
welds in the flat welding position
with ac, dcep, or dcen. These
electrodes are well suited for
thicker base metal.
E7024
[E4924]
The weld face is slightly convex to
flat, with a very smooth surface
and a very fine ripple.
E7024 [E4924] electrode coverings contain large amounts of iron
powder in combination with ingredients similar to those used in E6012
and E6013 [E4312 and E4313] electrodes. The coverings on E7024
[E4924] electrodes are very thick and usually amount to about 50
percent of the weight of the electrode, resulting in higher deposition
efficiency. These electrodes are characterized by a smooth, quiet arc,
very low spatter, and low arc penetration.
They can be used with high travel
speeds. Electrodes designated as
E7024-1 [E4924-1] have the same
general usability characteristics as
E7024 [E4924] electrodes. They are
intended for use in situations requiring
greater ductility and a lower transition
temperature than normally is available
from E7024 [E4924] electrodes.
E6022
[E4322]
The weld face tends to be more
convex and less uniform,
especially since the welding
speeds are higher.
Electrodes of the E6022 [E4322]
classification are recommended for
single- pass, high-speed, high-current
welding of groove welds in the flat
welding position, lap joints in the
horizontal welding position, and fillet
welds on sheet metal.
E6020
[E4320]
E6020 [E4320] electrodes have a high iron oxide covering. They are
characterized by a spray type arc.
The electrodes produce a smooth
and flat, or slightly concave weld
face and have an easily
removable slag.
A low viscosity slag limits
their usability to horizontal
fillets and flat welding
positions.
With arc penetration ranging from
medium to deep (depending upon
welding current), E6020 [E4320]
electrodes are best suited for thicker
base metal.
E6019
[E4319]
E6019 [E4319] electrodes, although very similar
to E6013 and E6020 [E4313 and E4320] electrodes in their coverings,
have distinct differences. E6019 [E4319] electrodes, with a rather fluid
slag system, provide deeper arc penetration and produce weld metal
that meets a 22-percent minimum elongation requirement, meets the
Grade 1 radiographic standards, and has an average impact strength
of 20 ft∙lbf [27J] when tested at 0°F [–20°C].
When welding in the vertical
welding position with upward
progression, weaving should be
limited to minimize undercut
While 3/16 in [5.0 mm] and
smaller diameter
electrodes can be used for
all welding positions
(except vertical welding
position with downward
progression), the use of
larger diameter electrodes
should be limited to the flat
or horizontal fillet welding
position..
31

SMAW Electrodes, Quick Selection
SMAW Electrode Quick Selection Guide
AWS Spec (AWS A5.1) -
E6010
E6011
E6013
E6019
E6027
E7016
E7018
E7024
E7028
E7048
E4303
E4310
E4311
E4313
E4319
E4327
E4916
UH10
E4918
H10
E4924
E4928
H15
E4948
H10
Covering / Coating Type
Lime-titania
High
cellulose-
Pottasium
High
Titania
Potassium
ilmenite
(FeTiO
3
)
high
iron
oxide,
iron
powder
Low
hydrogen
type
Low
hydrogen,
potassium,
Iron
powder,
titania
low
hydrogen,
potassium,
Low
hydrogen
type
Crack
Resistant
Ability
Normal Normal Normal Normal Normal Excel Excel Normal Good Excel
RT Quality Normal Normal Normal Normal Normal Excel Excel Normal Good Good
Impact
Performance Normal Normal Normal Normal Normal Excel Excel Normal Good Good
Operation Ability
Flat Excel Normal Excel Good Normal Normal Normal Normal Normal NA
Hori.Fillet Excel Normal Excel Good Excel Normal Normal Excel Excel NA
Vert.up Poor Normal Normal Good NA Excel Excel NA NA NA
Vert, down NA Excel Good Poor NA NA NA NA NA Excel
Hori, OH Poor Excel Good Good NA Normal Normal NA NA NA
Flat Excel Poor Excel Normal Normal Normal Normal Normal Normal NA
Hori.Fillet Excel Poor Excel Normal Excel Normal Normal Excel Excel NA
Vert, OH, Hori Poor Excel Good Normal NA Good Good NA NA Excel
Normal Excel Poor Good Poor Normal Normal Poor Poor Normal
Excel Excel Excel Normal Excel NA NA Excel Excel Poor
Normal Poor Good Normal Good Normal Normal Good Good Normal
Excel Normal Good Normal Good Good Good Good Good Excel
Good Poor Normal Normal Good Normal Normal Good Good Excel
Good Poor Excel Normal Poor Poor Poor Poor Poor Poor
Excel Excellent
Good Better Selection
Normal OK for the purpose
Poor Not recommended
NA Not Applicable
Importance of Welding Electrode Flux (related to AWS A5.1)
Welding
Position
Chapter-7
Welding
Performance
JIS Spec
Bead
Appearance
Spatter
Thin Plate Weld
Welding Speed
Slag Removal
Re-Arc ability
Penetration Depth
By JGC Annamalai
32

Chapter-8
Method of Manufacture (AWS A5.1, para: 19): says: The electrodes classified according to this specification
may be manufactured by any method that will produce electrodes that meet the requirements of this specification.
(1). Need for Quality :
(2). Pre-Production
(3). Production of SMAW Electrodes
(4). Packing and Distribution:
(5). Production of Covered Welding Electrode (Some Key Operations) :
Due to poor quality of weld and many weld failures, there were many accidents and deaths and loss of
properties in the initial period of welding, say, between 1920 to 1940. Standards were made to safe guard the
product quality. Now, users prefer , the electrodes are to be tested and accepted to Standards and
Specification. Popular standard for Welding Electrodes, is AWS A5.1 (Specification for Carbon Steel
Electrodes for Shielded Metal Arc Welding). Many users want testing and qualification for each batch of
production. AWS A5.1 is periodically revised / updated to reflect, user requirements, the industry problems,
technology advances etc.
Production of SMAW Electrodes
Mild Steel or Carbon Steel covered electrodes, also commonly called coated electrodes, consist of only two
major elements; the core wire or rod and the flux covering. The core wire is usually low carbon steel. It must
contain only small amounts of aluminum and copper, and the sulfur and phosphorous levels must be kept
very low so that undesirable brittleness in the weld metal is avoided. The raw material for the core wire is hot-
rolled rod (commonly called "hot rod" or AISI-1010). It is received in large coils, cleaned, drawn down to the
proper electrode diameter, straightened, and cut to the proper electrode length and coated.
The coating ingredients, (there are several hundreds), are carefully weighed, blended in a dry state, wet
mixed, and compacted into a large cylinder that fits into the extrusion press. The coating is extruded over the
cut core wires which are fed through the extrusion press at a rapid rate. The coating material is removed
from the end of the electrode that is clamped into the electrode holder to assure electrical contact, and also
from the welding end of the electrode to assure easy arc initiation.
The electrodes are then stamped with the type number for easy identification before entering the ovens.
Inside the oven, the electrodes go through a controlled bake cycle to insure the proper moisture content
before packaging. Normal pack is 5 kg for easy handling.
By JGC Annamalai
Coils from Steel Mills Coils Descalled, drawn, re-wound Flux ingredients, ready for Extrusion
Electrode Extrusion Plant Coated Electrodes, from Extrusion Plant Electrodes, stamped
Electrode Baking/Drying Oven Electrodes stacked for Packing Electrodes packed
33
(a)

Chapter-8 Production of SMAW Electrodes
By JGC Annamalai
5 Production Flow Diagram :
1
2
3
4
AWS A5.1: Method of Manufacture.
The electrodes classified according to
this specification may be
manufactured by any method that will
produce electrodes that meet the
requirements of this specification.
AWS A5.1, there is no mention, on
the size of the OD of the coating.
Requirements, testing etc are
discussed in Chapter-9
AWS A5.1 says : The core wire and
covering shall be free of defects that
would interfere with uniform
deposition of the electrode.
Normal electrode core wire is rimmed
steel, having 0.1% carbon(AISI
1010).
The raw material for the core wire is
hot-rolled rod (commonly called "hot
rod")
A5.1 (in) A5.1Mc (mm) A5.1 (in) A5.1M (mm)
1/16 1.6 9 225
5/64 2.0 9 or 12 225 or 300
3/32 — 12 or 14 —
— 2.5 — 300 or 350
1/8 3.2 14 350
5/32 4.0 14 or 18 350 or 450
3/16 — 14 or 18 —
— 5.0 — 350 or 450
7/32 — 14 or 18 or 28 —
— 6.0 — 350 or 450 or 700
1/4 — 18 or 28 —
5/16 8.0 18 or 28 450 or 700
Table 12
Electrodes, Standard Sizes and Lengths
Core Wire Diameter,a Lengths, a, b
a. Lengths and sizes other than these shall be as agreed between purchaser and
supplier.
b. In all cases, end-gripped electrodes are standard.
c. ISO 544 Welding consumables—Technical delivery conditions for welding filler
maerials—Type of product, dimensions, tolerances and markings. See 20.2 for
tolerances on diameter and length.
Tests are required to meet the Electrode Standard
and to meet user Spec. To have the Standard Name
on package, like AWS A5.1, Electrode Testing, is
mandatory. Normally, Tests are conducted
for each flux mixing/batch
Tests, per AWS A5.1
34

Chapter-8 Production of SMAW Electrodes
By JGC Annamalai
Drive Off Moisture for Better Welds : (AWS A5.1, Table-A3)
Low Hydrogen Electrodes : (at field)
(1). Drying or Backing oven: Just after opening pockets:
Reconditioning is done at 350°C, for minimum 1 hour.
(2). Holding or Portable ovens: Till use, the electrodes
are kept in portable ovens, kept at 120°C. After welding,
remaining Electrodes are returned to the
Reconditioning oven.
(3). Electrodes can be reconditioned, maximum 5
times. If the reconditioning exceeds 5 times, the
electrodes should be discarded.
(Temperature Range:
Adjustable 30 to 150°C)
(Temperature Range:
Adjustable 250 to 430°C)
(Holding Oven)
(Storage or Drying Oven)
35

Electrodes other than low hydrogen electrodes shall be tested without conditioning(Conditioning is any preparation or
procedure, such as baking the electrode, which the user would not normally practice).
Low-hydrogen electrodes, if they have not been protected against moisture pickup in storage, shall be held at a
temperature within the range 500°F to 800°F [260°C to 430°C] for a minimum of one hour prior to testing.
If the results of any test fail to meet the requirement, that test shall be repeated twice. If one or both specimen fail, the
test is considered failed and not meeting the AWS A5.1.
All tests shall be done or repeated, following proper prescribed procedures.
Electrode Requirements, Testing, Qualifications (1)
Acceptance of the Electrode, needs many Testing and approval. The following welded test assemblies/testing are
to be completed: The sample for chemical analysis may be taken from the reduced section of the fractured tension
test specimen
9.1 One or more of the following five weld test assemblies are
required:
Chapter-9
By JGC Annamalai
Moisture Testing: (Table-10)
A5.1 A5.1 (Stamped)
As-Received or
Conditioned
As-Exposed
E6018 E6018
E7015 E7015
E7016 E7016 / E7016-1
E7018 E7018 / E7018-1
E7028 E7028
E7048 E7048
E6018 E6018R
E7015 E7015R
E7016 E7016R / E7016-1R
E7018 E7018R / E7018-1R
E7028 E7028R
E7048 E7048R
E7018M E7018M 0.1 0.4
Unit-mL/100g of weld metal
0.6
Not Specified (not
accepted)
0.3 0.4
AWS A5.1
(Table-11)
Diffusible
Hydrogen
Designator
Diffusible H2, Ave in
mL/100g deposited
weld metal, max
E7018M None 4
E7015
E6018 H16 16
E7015 H8 8
E7016 H4 4
E7018
E7048
H16 16
H8 8
H4 4
1/16 1.6 9 225
5/64 2.0 9 or 12 225 or 300
3/32 — 12 or 14 —
— 2.5 — 300 or 350
1/8 3.2 14 350
5/32 4.0 14 or 18 350 or 450
3/16 — 14 or 18 —
— 5.0 — 350 or 450
7/32 — 14 or 18 or 28 —
— 6.0 — 350 or 450 or 700
1/4 — 18 or 28 —
5/16 8.0 18 or 28 450 or 700
Table 12
supplier.
AWS Classification UNS Combined Limit for
A5.1 A5.1M Number C Mn Si P S Ni Cr Mo V Mn+Ni+Cr+Mo+V
E6010 E4310 W06010 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6011 E4311 W06011 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6012 E4312 W06012 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6013 E4313 W06013 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6019 E4319 W06019 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6020 E4320 W06020 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6027 E4327 W06027 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6018 E4318 W06018 0.03 0.6 0.4 0.025 0.015 0.3 0.2 0.3 0.08 N.S.
E7015 E4915 W07015 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7016 E4916 W07016 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7018 E4918 W07018 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7014 E4914 W07014 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7024 E4924 W07024 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7027 E4927 W07027 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7028 E4928 W07028 0.15 1.6 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7048 E4948 W07048 0.15 1.6/0.4 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7018M E4918M W07018 0.12 1.6/0.4 0.8 0.03 0.02 0.25 0.15 0.35 0.05 N. S.
Chemical Composition Requirements for Weld Metal (Table-7)
Weight %
Notes: a). SAE/ASTM Unified Numbering System for Metals and Alloys. B). Single values are maximum. N. S. means Not Specified.
36
(a)

Electrode Requirements, Testing, Qualifications (1)
Chapter-9
By JGC Annamalai
Moisture Testing: (Table-10)
A5.1 A5.1 (Stamped)
As-Received or
Conditioned
As-Exposed
E6018 E6018
E7015 E7015
E7016 E7016 / E7016-1
E7018 E7018 / E7018-1
E7028 E7028
E7048 E7048
E6018 E6018R
E7015 E7015R
E7016 E7016R / E7016-1R
E7018 E7018R / E7018-1R
E7028 E7028R
E7048 E7048R
E7018M E7018M 0.1 0.4
Unit-mL/100g of weld metal
0.6
Not Specified (not
accepted)
0.3 0.4
AWS A5.1
(Table-11)
Diffusible
Hydrogen
Designator
Diffusible H2, Ave in
mL/100g deposited
weld metal, max
E7018M None 4
E7015
E6018 H16 16
E7015 H8 8
E7016 H4 4
E7018
E7048
H16 16
H8 8
H4 4
Grip End/Butt end
for electrode size,5/32" [4.0 mm] & small, bare
1/16 1.6 9 225
5/64 2.0 9 or 12 225 or 300
3/32 — 12 or 14 —
— 2.5 — 300 or 350
1/8 3.2 14 350
5/32 4.0 14 or 18 350 or 450
3/16 — 14 or 18 —
— 5.0 — 350 or 450
7/32 — 14 or 18 or 28 —
— 6.0 — 350 or 450 or 700
1/4 — 18 or 28 —
5/16 8.0 18 or 28 450 or 700
Table 12
supplier.
AWS Classification UNS Combined Limit for
A5.1 A5.1M Number C Mn Si P S Ni Cr Mo V Mn+Ni+Cr+Mo+V
E6010 E4310 W06010 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6011 E4311 W06011 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6012 E4312 W06012 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6013 E4313 W06013 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6019 E4319 W06019 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6020 E4320 W06020 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6027 E4327 W06027 0.2 1.2 1 N.S. N.S. 0.3 0.2 0.3 0.08 N.S.
E6018 E4318 W06018 0.03 0.6 0.4 0.025 0.015 0.3 0.2 0.3 0.08 N.S.
E7015 E4915 W07015 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7016 E4916 W07016 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7018 E4918 W07018 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7014 E4914 W07014 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7024 E4924 W07024 0.15 1.25 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.5
E7027 E4927 W07027 0.15 1.6 0.75 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7028 E4928 W07028 0.15 1.6 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7048 E4948 W07048 0.15 1.6/0.4 0.9 0.035 0.035 0.3 0.2 0.3 0.08 1.75
E7018M E4918M W07018 0.12 1.6/0.4 0.8 0.03 0.02 0.25 0.15 0.35 0.05 N. S.
Chemical Composition Requirements for Weld Metal (Table-7)
Weight %
Notes: a). SAE/ASTM Unified Numbering System for Metals and Alloys. B). Single values are maximum. N. S. means Not Specified.
max
Covering Eccentricity(para-21)
The diameter of the core wire shall not vary more than ±0.002 in [0.05 mm] from the diameter specified. The length
shall not vary more than ±1/4 in [10 mm] from that specified.
E7016 H4 4
E7018
E7048
H8 8
H4 4
Grip End/Butt end
for electrode size,5/32" [4.0 mm] & small, bare
end shall be >1/2"[12 mm] & <1-1/4"[30 mm]
for electrode size,<3/16" [5.0 mm] & larger, bare
end shall be >3/4" [20 mm] & <1-1/2 in [40 mm]
Arc End
1/8 in [3.2 mm] or the diameter of
the core wire, whichever is less
E7018
<2-1/2" [65 mm] of the grip
end of the electrode
Electrode
Stamping
Letters, Bold Block type of a size large enough
to be legible. Ink is contrasting to the surface
ASME QW-432 F Numbers grouping of electrodes and welding rods for qualification
"F" Numbers are Filler Number
QW "F" No ASME Specification No AWS Classification No
432.1 1 SFA-5.1 and 5.5 EXX 20, EXX 24, EXX 27, EXX 28
2 SFA-5.1 and 5.5 EXX 12, EXX 13, EXX 14
3 SFA-5.1 and 5.5 EXX 10, EXX 11
4 SFA-5.1 and 5.5 EXX 15, EXX 16, EXX 18
4 SFA-5.4 Nom. Total Alloy 6 % or less EXX 15, EXX 16
4 SFA-5.4 Nom. Total Alloy more than 6 % EXX 15, EXX 16
5 SFA-5.4 Cr-Ni Electrode EXX 15, EXX 16
6 SFA-5.2 RGXX
6 SFA-5.17 FXX-XXXX
6 SFA-5.9 ERXX
6 SFA-5.18 EXXS-X,EXXU-X
6 SFA-5.20 EXXT-X
6 SFA-5.22 EXXXT-X
6 SFA-5.23
FXX-EXXX-X, FXX-ECXXX-X and
FXX EXXX-XN, FXX-ECXXX-XN
6 SFA-5.28 ER-XXX-X and E-XXX-X
"F" Numbers
QW "A" No Types of weld deposit C % Cr % Mo % Ni % Mn % Si %
442 1 Mild Steel 0.15 1.60 1.00
2 Carbon-Moly 0.15 0.50 0.40-0.65 1.60 1.00
3 Chrome (0.4 to 2 %)-Moly 0.15 1.40-2.00 0.40-0.65 1.60 1.00
4 Chrome (2 to 6 %)-Moly 0.15 2.00-6.00 0.40-1.50 1.60 2.00
5 Chrome (6 to 10.5 %)-Moly 0.15 6.00-10.50 0.40-1.50 1.20 2.00
6 Chrome-Martensitic 0.15 11.00-15.00 0.70 2.00 1.00
7 Chrome-Ferritic 0.15 11.00-30.00 1.00 1.00 3.00
8 Chromium-Nickel 0.15 14.50-30.00 4.00 7.50-15.00 2.50 1.00
9 Chromium-Nickel 0.30 25.00-30.00 4.00 15.00-37.00 2.50 1.00
10 Nickel to 4 % 0.15 0.55 0.80-4.00 1.70 1.00
11 Manganese-Moly 0.17 0.25-0.75 0.85 1.25-2.25 1.00
12 Nickel-Chrome-Moly 0.15 1.50 0.25-0.80 1.25-2.80 0.75-2.25 1.00
"A" NUMBERS ANALYSIS*
* Single values shown above are maximum.
"A" Numbers are "Weld Analysis Number"
ASME QW-442 "A" numbers classification of weld metal analysis for Procedure Qualification
Rod(Core) dia=d
Normal Covering dia=D
Core+max.covering)=D1
Core +min.covering=D2
Covering
max
min
Max. Eccentricity :
(1) 7 % in dia sizes 3/32 in [2.5 mm] and smaller
(2) 5% in dia sizes 1/8 in [3.2 mm] and 5/32 in [4.0 mm]
(3) 4% in dia sizes 3/16 in [5.0 mm] and larger
Covering Eccentricity(para-21)
Eccenticity=(D1-D2)(100/D)
37

Average Single
Value
Chemical
Analysis(T
able 7)
RT & All-Weld
metal Tension
Test,
Para.11.0
Impact
Test
(para
14.0)
Fillet Weld
Test(para
15.0)
Moisture
Test(par
a 16,17)
E6010 High cellulose sodium F, V, OH, H DCEP 60 48 22 27 J @–30°C
20 J @–30°C F F F V&H NR
E6011 High cellulose potassium F, V, OH, H AC OR DCEP 60 48 22 27 J @–30°C
20 J @–30°C F F F V&H NR
E6012 High titania sodium F, V, OH, H AC OR DCEN 60 48 17 Not Specified
Not Specified F F NR V&H NR
E6013 High titania potassium F, V, OH, H AC, DCEP, OR DCEN 60 48 17 Not Specified
Not Specified F F NR V&H NR
E6018 Low-hydrogen potassium, iron powder
F, V, OH, H AC OR DCEP 60 48 22 27 J @–30°C
20 J @–30°C F F F V&H REQD
E6019 Iron oxide titania potassium F, V, OH, H AC, DCEP, OR DCEN 60 48 22 27 J at –20°C]
20 J at –20°C] F F F V&H NR
E6020 High iron oxide H-fillet/F AC OR DCEN/DCEP 60 48 22 1 Not Specified F F NR H, Fillet NR
E6022 High iron oxide F, H-fillet AC OR DCEN 60 Not Specified
Not Specified
Not Specified
Not Specified NR F NR NR NR
E6027 High iron oxide, iron powder H-fillet/F AC OR DCEN/DCEP 60 48 22 27 J @–30°C
20 J @–30°C F F F H, Fillet NR
E7014 Iron powder, titania F, V, OH, H AC, DCEP, OR DCEN 70 58 17 Not Specified
Not Specified F F NR V&OH NR
E7015 Low-hydrogen sodium F, V, OH, H DCEP 70 58 22 27 J @–30°C
20 J @–30°C F F F V&OH REQD
E7016 Low-hydrogen potassium F, V, OH, H AC OR DCEP 70 58 22 27 J @–30°C
F, V, OH, H AC OR DCEP 70 58 22 27 J @–30°C
E7018M Low-hydrogen iron powder F, V, OH, H DCEP 70 58 17e 27 J @–30°C
20 J @–30°C F V V NR REQD
E7024 Iron power, titania H-fillet, F AC, DCEP, OR DCEN 70 58 22 Not Specified
Not Specified F F F H, Fillet NR
E7027 High iron oxide, iron powder H-fillet/F AC OR DCEN/DCEP 70 58 22 27 J @–30°C
20 J @–30°C F F F H, Fillet NR
H-fillet, F AC OR DCEP 70 58 22 27 J at –20°C]
20 J at –20°C] F F F H, Fillet REQD
F, OH, H, V-down
AC OR DCEP Note f 53–72g 24 27 J @–30°C
20 J @–30°C F F F V, Down&OH REQD
Table-1
Table-2
Table-3
Table-4
Table-1 Table-2 Table-3 Table-4
AWS
Classificati
on
Type of Covering Welding
Position
Type of Current Tensile
Strengt
h (ksi)
Yield
Strength
(0.2%
Offset),
ksi
a). NR means “not required.” The abbreviations, F, H-fillet, V-down, V, and OH are defined in Note a of Table 1. The terms “dcep” and “dcen,” are defined in Note b of Table 1.b). Standard electrode sizes not
requiring this specific test can be classified provided at least two other sizes of that classification have passed the tests required for them, or the size to be classified meets specification requirements by having
been tested in accordance with Figures 1, 2, and 3 and Table 6. c). See Section 10. d). See Section 11. e). See Section 12. f). See Section 14. g). See Section 15. h). A radiographic test is not required for this
classification. i) The moisture test given in Section 16 is the required test for moisture content of the covering. In Sections 17 and 18 are supplemental tests required only when their corresponding optional
supplemental designators are to be used with the classification designators. j. An all-weld-metal tension test is not required for E6022 electrodes. Instead, a transverse tension test (see 12.5) and a longitudinal
guided bend test (see Section 13) are required for classification of 5/32 in, 3/16 in, and 7/32 in [4.0 mm, 5.0 mm, and 6.0 mm] E6022 [] electrodes. k. When dcep and dcen are shown, only dcen need be tested. l.
Electrodes longer than 18 in [450 mm] will require a double length test assembly in accordance with Note 1 of Figure 2, to ensure uniformity of the entire electrode. m.Tests in Section 17, and in Section 18, are
required for all sizes of E7018M . n. Electrodes identified as E7024-1 shall be impact tested (see Note b of Table 3).
Elangati
on,
%(min.
length,4
xdia)
Impact Test Required Test for 4mm dia electrode, Other sizes refer to Table-4)
a). The abbreviations, the welding positions: F = Flat, H-fillets = Horizontal fillet, V = Vertical, progression upwards (for electrodes 3/16 in [5.0 mm] and under, except 5/32 in [4.0 mm] and under for
classifications E6018 , E7014, E7015, E7016, E7018, E7018M, E7048). V-down = Vertical, progression downwards (for electrodes 3/16 in [5.0 mm] and under, except 5/32 in [4.0 mm] and under for
classifications E6018, E7014, E7015, E7016, E7018, E7018M, E7048), OH = Overhead (for electrodes 3/16 in [5.0 mm] and under, except 5/32 in [4.0 mm] and under for classifications E6018, E7014, E7015,
E7016, E7018, E7018M,E7048).
b). The term “dcep” refers to direct current electrode positive (dc, reverse polarity). The term “dcen” refers to direct current electrode negative (dc, straight polarity).
c). Electrodes with supplemental elongation, notch toughness, absorbed moisture and diffusible hydrogen requirements may be further identified (Tables 2, 3, 10, 11).
d). Electrodes of the E6022 [E4322] classification are intended for single-pass welds only.
a). See Table 4 for sizes to be tested., b). Requirements are in the as-welded condition with aging as specified in 12.2. c.) Single values are minimum. d). A transverse tension test, as specified in 12.5 and a
longitudinal guided bend test, as specified in Section 13 are required. e). Weld metal from electrodes identified as E7024-1 shall have elongation of 22% minimum. f). Tensile strength of this weld metal is a
nominal 70 ksi [490 MPa]. g). For 3/32 in [2.4 mm] electrodes, the maximum yield strength shall be 77 ksi [530 MPa].
a). Both the highest and lowest test values obtained shall be disregarded in computing the average. Two of these remaining three values shall exceed 20 ft∙lbf [27 J]. b). Electrodes with the following optional
supplemental designations shall meet the lower temperature impact requirements specified below: c). All five values obtained shall be used in computing the average. Four of the five values shall equal, or
exceed, 50 ft∙lbf [67 J].
TEST REQUIREMENTS-2
(For detailed info, please refer to the Original Spec, AWS A5.1).
MoistureTesting:(Table-10) Unit-mL/100gofweldmetal
Chapter-9 38 (b)

The Importance of Welding Electrode Flux Coating

The Importance of Welding Electrode Flux Coating

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