alloy structure 1008

1018 Mild Steel
Alloy 1018 is the most commonly available of the cold-rolled steels. It is generally available in round rod, square bar,
and rectangle bar. It has a good combination of all of the typical traits of steel - strength, some ductility, and
comparative ease of machining. Chemically, it is very similar to A36 Hot Rolled steel, but the cold rolling process
creates a better surface finish and better properties.
1018 Mild (low-carbon) steel
Ultimate Tensile Strength, psi 63,800
Yield Strength, psi 53,700
Elongation 15.0%
Minimum Properties
Rockwell Hardness B71
Iron (Fe) 98.81 - 99.26%
Carbon (C) 0.18%
Manganese (Mn) 0.6 - 0.9%
Phosphorus (P) 0.04% max
Chemistry
Sulfur (S) 0.05% max
A36 Mild Steel
ASTM A36 steel is the most commonly available of the hot-rolled steels. It is generally available in round rod, square
bar, rectangle bar, as well as steel shapes such as I-Beams, H-beams, angles, and channels. The hot roll process
means that the surface on this steel will be somewhat rough. Note that its yield strength is also significantly less than
1018 - this means that it will bend much more quickly than will 1018. Finally, machining this material is noticeably
more difficult than 1018 steel, but the cost is usually significantly lower.
ASTM A36 Mild (low-carbon) steel
Ultimate Tensile Strength, psi 58,000 - 79,800
Yield Strength, psi 36,300
Minimum Properties
Elongation 20.0%
Iron (Fe) 99%
Carbon (C) 0.26%
Manganese (Mn) 0.75%
Copper (Cu) 0.2%
Phosphorus (P) 0.04% max
Chemistry
Sulfur (S) 0.05% max
1144 (Stressproof-equivalent) steel
This material is actually pretty cool, at least for steel. It is a higher-strength alloy than 1018 or A36, but in addition has
improved ductility as well. The chief feature of 1144 steel, however, is that it has very low distortion or warpage after
machining due to a combination of its chemistry, method of manufacture, and heat treatment. Finally, 1144 is
relatively easy to machine, with a machinability rating of 83% of AISI 1212 steel.
1144 (Stressproof-equivalent) steel
Ultimate Tensile Strength, psi 115,000
Yield Strength, psi 100,000
Elongation 8.0%
Minimum Properties
Rockwell Hardness B95 / C17
Iron (Fe) 97.54 - 98.01%
Carbon (C) 0.4 - 0.44%
Manganese (Mn) 1.35 - 1.65%
Phosphorus (P) 0.04% max
Chemistry
Sulfur (S) 0.24 - 0.33%
12L14 free machining steel
This alloy has lead added to the mix in order to enhance its machinability. In fact, it is rated with a machinability of
160% of AISI 1212 steel. The addition of lead does, however, reduce the strength of this alloy, although it is generally
stronger than 1018.
12L14 free machining steel
Ultimate Tensile Strength, psi 78,300
Yield Strength, psi 60,200
Elongation 10.0%
Minimum Properties
Rockwell Hardness B84
Iron (Fe) 97.91 - 98.7%
Carbon (C) 0.15% max
Manganese (Mn) 0.85 - 1.15%
Phosphorus (P) 0.04 - 0.09%
Lead (Pb) 0.15 - 0.35%
Chemistry
Sulfur (S) 0.26 - 0.35%
A653 Galvanized Steel
Galvanized steel is simply hot rolled steel to which a zinc coating has been applied for protection against corrosion.
ASTM A653 Mild (low-carbon) Hot Dipped Galvanized Steel
Ultimate Tensile Strength, psi 58,000 - 79,800
Yield Strength, psi 36,300
Minimum Properties
Elongation 20.0%
Iron (Fe) 99%
Carbon (C) 0.26%
Manganese (Mn) 0.75%
Copper (Cu) 0.2%
Phosphorus (P) 0.04% max
Chemistry
Sulfur (S) 0.05% max
A366/1008 Steel
This alloy is generally used for "commercial quality" cold rolled steel sheet. It is known for its very good formability
and comparatively high strength. It has a very good surface finish that is far superior to hot rolled A36.
ASTM A366 (alloy 1008) steel
Ultimate Tensile Strength, psi 43,900 - 51,900
Yield Strength, psi 26,100 - 34,800
Minimum Properties
Elongation 42 - 48%
Iron (Fe) 99%
Carbon (C) 0.08%
Manganese (Mn) 0.6% max
Phosphorus (P) 0.035% max
Copper (Cu) 0.2% min
Chemistry
Sulfur (S) 0.04%
A513 (alloy 1020-1026) Steel
This alloy is generally used for DOM tubing. Its higher carbon content means higher strength, but lower weldability
and machinability.
ASTM A513 alloys 1020 - 1026 Mild (low-carbon) steel
Ultimate Tensile Strength, psi 87,000
Yield Strength, psi 72,000
Elongation 10.0%
Minimum Properties
Rockwell Hardness B89
Iron (Fe) 99.08 - 99.53%
Carbon (C) 0.18 - 0.23%
Manganese (Mn) 0.3 - 0.6%
Phosphorus (P) 0.04% max
Chemistry
Sulfur (S) 0.05% max
8620 Alloy Steel
This material is characterized by a hard outer surface, combined with a ductile interior for higher strength.
8620 (chrome-nickel-moly) Alloy Steel
Tensile Strength, psi 97,000
Yield, psi 57,000
Brinell Hardness 201
Elongation 25%
Minimum Properties
Machinability 66%
Carbon (C) 0.18 - 0.23%
Manganese (Mn) 0.7 - 0.9%
Phosphorus (P) 0.35% Max
Sulphur (S) 0.4% Max
Silicon (Si) 0.15 - 0.35%
Chromium (Cr) 0.4 - 0.6%
Nickel (Ni) 0.4 - 0.7%
Chemistry
Molybdenum (Mo) 0.15 - 0.25% max