1. Steel Stainless Steel Cast Iron Copper/Brass Aluminum
The 5 Base Metals
Steel
Stainless Steel
Cast Iron
Copper/Brass
Aluminum

2. Steel – A Ferrous Metal A iron alloy containing less than 2% carbon
Melting point of 1535 degrees C or 1535 degrees F 2795
Boils at 3000 degrees C or 5432 degrees F
From Iron, add coke, limestones lots of air and boom steel is created

3. Steel Forms
Bars – Solid shapes, hot or cold rolled, rounds, squares, or flats
Billets – A section of an ingot
Blooms – A slab of steel, usually the same thickness and width
Plates – Large flat slabs thicker than ¼” (inch)
Shapes – Can be in the forms of beams or any other shape needed
Sheets – Hot or cold rolled with varying thicknesses
Wires – Drawn form bars of steel

4. Steel Nomenclature Created by S.A.E and A.I.S.I
Referred to by a four digit designation (e.g. 1060, 8620, 4340)
The first two digits refer to types of alloys in the steel (e.g means it is plain carbon)
The last two digits refer to the carbon content in hundredths (e.g is .18% carbon.
1018 means that we have a plain carbon steel with .18% carbon

5. Stainless Steel – A Ferrous Metal
A iron alloy containing less than 2% carbon
Contains chromium and sometimes nickel
Melting point of 1535 degrees C or 2795 degrees F
Boiling point of 3000 degrees C or 5432 degrees F
Why do we use Stainless Steel?
Better aesthetics
Minimizes oxidation and corrosion
Can have the ability to be ultrahigh-strength steel

6. Stainless Steel Classification
Designated with the same 4 digit coding of steel
Ferritic
11 to 27 percent chromium
Low carbon content (.1 to .35 percent)
Used in jewelry, car accessories, and is considered very weak
Austenitic
Non-magnetic
16 to 26 chromium and 6 to 22 percent nickel
Very low carbon content
Wieldable, somewhat machinable, but cannot be hardened by heat treatments
Used in low strength structural purposes
Martensitic
Higher carbon content .15 to 1.2 percent
4 to 18 percent chromium with usually no nickel
Magnetic
Not easily machined or welded but possible
Good for knives and such

7. Cast Iron – A Ferrous Metal
Contains 2% or more carbon
Can be Gray, White, Ductile, Malleable, or Wrought
Somewhat unpredictable to work with due to its high carbon content
Two most common are Gray and White

8. Cast Iron Gray Most Common type of cast iron About 4% carbon
Cheap to make, good compression strength, good machinability, and good vibration dampening
Broken up into three classes based on minimum tensile strength
Class 20 – 20,000 lb/in^2
Class 40 – 40,000 lb/in^2
Class 60 – 60,000 lb/in^2

9. Cast Iron
White
2.5 to 3.5 percent carbon and .5 to 1.5 percent silicon and 1 to 3 percent nickel, molybdenum, or chromium
Same class system as Gray Cast Iron
Very hard and very brittle
Great wear resistance
Ideal for rolling/crushing machines or tools

10. Cast Iron Ductile – ability to be drawn into a wire
4% carbon and 2.5% silicon
Is composed of spherulites (Key factor in the ductile part)
This removes the stress risers which potentially allow cracking in the metal
Tensile strength at around 120,000 lb/in^2
Designated by three individual number sets
e.g. 60:40:18, 65:45:12
First Set – Tensile Strength (amount of energy required to rip the material apart)
Second Set – Yield Strength (the point at which the material begins to deform)
Third Set – Percent Ultimate Elongation (the permanent deformation of the material)

11. Copper/Brass – A Non-ferrous Metal
One of the first metals used
Dozens of types of ores but not many are commercially important
Predominantly found in Michigan, Utah, Nevada, Montana, Arizona, Alaska, Chile, Canada, Africa, England, Spain, Peru, Mexico, and Bolivia
Most practical copper is found near the surface of the earth
Usually used for wire and electrical components (must be extremely pure)
Good conductivity and good corrosion resistance but will react with sulfur, oxygen, and chlorine when heated
Its tensile strength is considerably less than steel and it modulus of elasticity is roughly half that of steel

12. Copper/Brass Continued
A type of Copper, Bronze, and Zinc
However may contain more elements besides Copper and Zinc
Roughly, Brass is 70% Copper, 29% Zinc, and 1% Tin
Most common types are Muntz, Red, and Free Machining
Muntz – also called Malleable Brass, is 60% Copper and 40% Zinc
Tensile strength of 52,000 lb/in^2
Red – 85% Copper and 15% Zinc
Tensile strength of 38,000 lb/in^2 but can be cold rolled (Hardened) to 70,000 lb/in^2
Free Machining
60% Copper, 40% Zinc, .75% Tin, and .25% Lead

13. Aluminum – A Non-ferrous Metal
Second most abundant metallic element in the Earth’s crust
Never found in a pure natural form
1/3 the weight of steel or copper
Easily recyclable (maintaining 100% reuse)
Melting Point: 1, degrees Fahrenheit ( degrees Celsius)
Boiling Point: 4,566 degrees F (2,519 degrees C)
Refined made readily useable by the Bayer and Hall–Héroult processes

14. Aluminum Continued Why do we use Aluminum? Light in weight Strong
Noncorrosive
Nonsparking
Nonmagnetic
Nontoxic
Noncombustible.

15. Aluminum Continued Aluminum is a very versatile metal
It is used in the auto and aero space industry due to lightness and durability
It is used in many situations where sparks or fire are concerns
It is generally thought of as more versatile than steel

16. Aluminum Continued Aluminum Code System
Good online sources ( aluminum-alloy-designation-system.cfm and )
Wrought Aluminum (4 digit codes)
Cast Alloy Designation (3 digit codes)
The Aluminum Temper Designation (letter designation)
F (As Fabricated) O (Annealed) H (Strain Hardened) W (Solution Heat Treated) T (Thermally Treated)
Commercial Grading (8 digit code)

18. Formability or Workability
Weldability
Machining
Corrosion Resistance
Heat Treating
Strength
Typical Applications
Alloy 1100
Excellent
Good No
Low
Metal Spinning
Alloy 2011
Poor
Yes
High
General Machining
Alloy 2024
Fair
Aerospace Application
Alloy 3003
Medium
Chemical Equipment
Alloy 5052
Marine Applications
Alloy 6061
Structural Applications
Alloy 6063
Architectural Applications
Alloy 7075
Average
Aerospace Applications