1. Adjusting And Setup of Welding
Equipment

2. Objectives:
•The students will recap on safety in the
shop & welding procedures.
•The students will be able to recognize
parts and tools used for welding.
•Students will be able to define terms used
in welding.
•Students will be able to describe the
welding process.

3. Terms And Definitions
Arc Welding – Process of using an electric arc as the source of
heat to join two or more pieces of metal by the fusion process.

4. Terms and Definitions
Arc – flow of electric current across a
narrow gap.

5. Terms and Definitions
Base metal – metal to be welded.

6. Terms and Definitions
Flux – Chemical coating on electrodes; used to promote
fusion of metals during welding.

7. Terms and Definitions
Bead Weld – Weld made by one pass of the
electrode.

8. Terms and Definitions
Pad – piece of practice metal on which parallel
beads are deposited side by side.

9. Terms and Definitions
Tack Weld – Small weld used to hold base
metals together temporarily.

10. Terms and Definitions
Slag – Nonmetallic by-product of welding process;
made of flux and nonmetallic impurities.

11. Terms and Definitions
Spatter – Deposit of small spots or particles of metal on the
base metal long side of the bead.

12. Terms and Definitions
Porosity – Condition caused by a trapped gas pocket
in a weld as it solidifies.

13. Kinds of shielded metal Arc Welding
Machines
• Alternating Current (AC)
– Machine that
alternates direction of
flow of electric current
120 times per second.

14. Kinds of shielded metal Arc Welding
Machines
• Direct Current (DC)
machine in which the
electric current flows in
one direction.

15. Kinds of shielded metal Arc Welding
Machines
• Alternating / direct
current (AC/DC) –
Machine that is capable
of supplying AC or DC
current for welding.

16. Common Arc Welding Equipment
• Welding Machine • Electrode holder with
lead

17. Common Arc Welding Equipment
• Ground clamp with lead • Welding Helmet

18. Common Arc Welding Equipment
• Leather Gloves • Chipping Hammer

19. Common Arc Welding Equipment
• Eye Protection • Wire Brush

20. Common Arc Welding Equipment
• Electrodes

21. Meanings of Characters in the AWS
Electrode Classification System
• Tensile
• Strength
• (Thousands Welding
• of pounds Position
• Electrode Welding Current
• And / Or Depth Of
• Penetration
• E 6012
• 1. Letter E – denotes that electrode is for arc welding.
• 2. First two numerals – indicates tensile strength in thousands of pounds
per square inch.
• 3. Third numeral – indicates position to be used.
• 4. Fourth numeral – gives code for special characteristics of electrode.

22. Purposes Of Flux
• 1. Stabilizes arc
• 2. Shielding molten
puddle from air.
• 3. Floating impurities
out of puddle.
• 4. Forming slag, which
slows cooling.
• 5. Increasing speed.

23. Methods of establishing arc
• 1. Scratching (similar to • 2. Tapping
striking a match)

24. Characteristics of proper arc length
• 1. End of electrode is
same distance from
base metal as diameter
of electrode.
• 2. Steady hum from
welding machine and
“frying” sound at the
arc.

25. Arc Welding Safety
• Always weld in a well
ventilated area. If
proper ventilation is not
available, go outside.

26. Arc Welding Safety
• Never look at a welding arc
with the naked eye.
• Do not strike an arc until
you are sure those in the
vicinity have protective
equipment or have turned
their eyes away from the
arc.

27. Arc Welding Safety
• Use eye protection when
chipping slag from a weld.
• Always wear suitable
clothing (long sleeves,
gloves, heavy pants, heavy
boots) to protect the body
from arc burns and spatter
of hot metal.

28. Arc Welding Safety
• Don not weld around
combustible materials.
• Do not weld on containers
that may contain
combustible substances.

29. Arc Welding Safety
• Do not leave electrode
holder on the table or in
contact with a grounded
metal surface.
• Do not use the welder on
or around wet surfaces.

30. Arc Welding Safety
• Place hot electrode stubs in
a metal container for
disposal. Never throw them
on the floor.
• Make sure all connections
are tight before welding.