ferrous and non ferrous materials

1. Identifying Materials
Liam Pourhana

2. As a craftsman, you will work with a variety of
materials. In this module, you will learn about
the most common metals and their properties,
such as hardness, color, corrosion resistance,
and brittleness
Also as a craftsman you will use several types
of metals. You must know how to identify each
type.
There are two classes of metals: ferrous and
non-ferrous. Ferrous metals have iron content.
Ferrous metals are iron and steel. Metals other
than iron and steel are classed as non-ferrous
metals.

3. FERROUS METALS
The most commonly used ferrous metals are:
o cast iron
o carbon steels
o stainless steel
Cast Iron
Iron for commercial use is mixed with carbon.
Cast iron is a ferrous metal. Cast iron is dark
gray and dull in appearance. After machining,
it may appear bright and shiny.
Manufacturers make items of cast iron by
pouring the molten iron into pre-shaped
molds, then allowing the metal to cool. That
process is known as casting the iron. When a
casting is cool and outside the mold, it is ready
for use or for any machining it may need.
However, cast iron is very brittle.
Brittle means that it will break
easily when struck with force. You
cannot bend it. Shock blows easily
crack or break cast iron. Other
substances added to cast iron give
the metal special qualities. For
example, adding small amounts of
silicon makes cast iron easier to
machine

4. Carbon Steels
Steels are also an alloy of iron and carbon.
Therefore, steels are ferrous metals. Carbon is
the most important element in all types of
steel. The form and amount of carbon content
control the properties of steel. Increasing the
carbon content increases its tensile strength,
hardness, and the response of the steel to
various heat-treatment processes. An increase
in carbon makes it more difficult to work with.
You can work low-carbon steel with
hand tools and machine tools. You
can bend thin-section low-carbon
steel when it is cold. However, you
need to add heat to bend heavy
Low-Carbon Steel
Low-carbon steel is the most common of the
carbon steels, and is usually know as mild
steel. It normally has a range of carbon content
in it of 0.05–0.3%. The color of low-carbon
steel and other carbon steels is light gray. After
machining, the steels appear bright and shiny.
Uses of low-carbon steel include
bar, shafts, pipe, plate, and
threaded fasteners. Other
examples are metal furniture,
machine skids, and low-pressure
pipe work.

5. Medium-Carbon Steel
Working with medium-carbon steel with hand tools and machine is more
difficult than working with low-carbon steel. Medium-carbon steel exhibits
much greater strength than low-carbon steel, and does not bend as easily
without heat. It normally has a range of carbon content in it of 0.3–0.6%.
An important characteristic of medium-carbon steel is its ability to harden
with heat. Many cutting tools made from medium-carbon steel have
hardened cutting edges.
In addition to cutting tools, medium-carbon steel is in such shop stock items
as bar, shafting, pipe, and plate. Other uses of medium-carbon steel are
fasteners, fabrications and pipe work that must withstand high pressures and
stresses, hand tools, and machine levers.

6. High-Carbon Steel
High-carbon steel is an alloy of iron and carbon. It has the highest percentage of
carbon of all carbon steels. Because of its high carbon content, it is very hard
and brittle. It normally has a range of carbon content in it of 0.6–1.0%.
Because it is very hard, you cannot file high-carbon steel or cut it with a
hacksaw. However, you can shape it with a grinding machine. You can bend
high-carbon steel if you first apply heat.
Most high-quality, high-carbon steel products do not corrode. Some of the
lower-quality products have coatings to protect them against corrosion.
High-carbon steel makes good metal cutting tools. Such tools include twist drill
bits, lathe machine cutting tools, taps and dies.

7. Stainless Steel
Stainless steel is a ferrous metal, an alloy of iron, carbon,
and chromium. The chromium content ranges upward
from 10.5%. Like the carbon steels, stainless steel is light
gray and appears bright and shiny when machined.
While a ferrous metal, many grades of stainless steel are
not magnetic. A simple check with a magnet may help you
to identify if the metal is ferrous or non-ferrous.
Under normal conditions, stainless steel does not corrode
easily. Stainless steel is highly resistant to corrosion and
attack by acids. Its use is for equipment that might corrode.
Such equipment includes pump impellers and shafts,
mechanical seals, measuring instruments, and valves.
Some fabrications and pipe work that require a combination
of strength and corrosion-free properties use stainless steel.
Shop stock items made of stainless steel include shafts,
pipes, and plates. Some threaded fasteners come in stainless
steel.

8. NON-FERROUS METALS
The term, non-ferrous, is used to indicate
metals other than iron and alloys that do not
contain an appreciable amount of iron. Most
non-ferrous metals are easy to work. However,
you should avoid grinding them, as grinding
will clog up the grinding wheel.
The most common non-ferrous metals used
are:
o aluminum
o copper and its alloys
o lead
Aluminum
Aluminum is a base metal that is
strong, soft, and lightweight. When
alloyed with other substances, it
gives special qualities. For example,
an aluminum alloy that contains
silicon is much harder than pure
aluminum.
The natural color of aluminum is
silver-gray. Its color can change with
different processes.
Copper and its Alloys
Copper is a base metal, reddish brown in color, and is easy to work with hand tools
and machine tools. Copper resists corrosion. However, copper turns green if it is
exposed to air over time.
Copper becomes hard with age and with constant vibration. However, when it is
heat-treated by annealing, it returns to its normal soft state. You can bend copper
without heating it.
You find many copper parts and equipment in the workshop. These include piping
and tubing, and soft jaws for vises.

9. Bronze
Bronze is an alloy of copper and tin. Bronze is a
yellow-orange metal. Like copper and
aluminum, it is easy to work with tools. Bronze
resists corrosion. And, because it wears well,
bronze makes good bearings and bushings.
Bronze goes into tools, as pipe fittings and
packing glands.
Brass
An alloy of copper and zinc, brass is
harder than copper. However, brass
still is a soft metal. Brass is yellow
and appears shiny when you
machine it. It is very easy to work
with tools. Like copper, bronze, and
aluminum, brass is too soft to
grind. Brass also has a low melting
point.
Brass resists corrosion very well.
Many cast or formed shop stock
items and machine parts come in
brass. Examples are metal bar, rod,
and sheeting. It also makes good
threaded fasteners and bushings.
Brass is also a good conductor of
electricity.
LEAD
Lead is a soft, malleable metal, also considered
to be one of the heavy metals. Lead has a
bluish white color when freshly cut, but
tarnishes to a dull grayish color when it is
exposed to air and is a shiny chrome silver
color when melted into a liquid.

10. Casting
Manufacturing process by which a liquid
material is usually poured into a mold, which
contains a hollow cavity of the desired shape,
and then allowed to solidify.
Cold Working
Altering the shape or size of a metal
by plastic deformation (when the
material is cold).
Machining
Machining is one of the most important
material removal methods. It is a collection of
material-working processes in which power-
driven machine tools, such as lathes, milling
machines, and drill presses are used with a
sharp cutting tool to mechanically cut the
material.
Normalizing
To restore to a normal condition.
Quenching
Rapid cooling from a high temperature by
immersion in a liquid bath of oil or water.
Welding
Welding is the most common way of
permanently joining metal parts. In this
process, heat is applied to metal pieces,
melting and fusing them to form a
permanent bond.