Carbon Steel

Carbon Steel and Alloy Steel

Marco is a supplier of carbon steel wire cloth and gratings. We carry a variety of carbon steel grades including: 1018, A36, 1144, 12L14, A366/1008, A513 & 8620.

There are four types of carbon steel based on the amount of carbon present in the alloy. Lower carbon steels are softer and more easily formed, and steels with a higher carbon content are harder and stronger, but less ductile, and they become more difficult to machine and weld. Below are the properties of the grades of carbon steel:

  • Low Carbon Steel: Composition of 0.05%-0.25% carbon and up to 0.4% manganese. Also known as mild steel, it is a low-cost material that is easy to shape. While not as hard as higher-carbon steels, carburizing can increase its surface hardness.
  • Medium Carbon Steel: Composition of 0.29%-0.54% carbon, with 0.60%-1.65% manganese. Medium carbon steel is ductile and strong, with long-wearing properties.
  • High Carbon Steel: Composition of 0.55%-0.95% carbon, with 0.30%-0.90% manganese. It is very strong and holds shape memory well, making it ideal for springs and wire.
  • Very High Carbon Steel: Composition of 0.96%-2.1% carbon. Its high carbon content makes it an extremely strong material. Due to its brittleness, this grade requires special handling.


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

Minimum PropertiesUltimate Tensile Strength, psi58,000 - 79,800
Yield Strength, psi36,300
ChemistryIron (Fe)99%
Carbon (C)0.26%
Manganese (Mn)0.75%
Copper (Cu)0.2%
Phosphorus (P)0.04% max
Sulfur (S)0.05% max


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

Minimum PropertiesUltimate Tensile Strength, psi63,800
Yield Strength, psi53,700
Rockwell HardnessB71
ChemistryIron (Fe)98.81 - 99.26%
Carbon (C)0.18%
Manganese (Mn)0.6 - 0.9%
Phosphorus (P)0.04% max
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

Minimum PropertiesUltimate Tensile Strength, psi115,000
Yield Strength, psi100,000
Rockwell HardnessB95 / C17
ChemistryIron (Fe)97.54 - 98.01%
Carbon (C)0.4 - 0.44%
Manganese (Mn)1.35 - 1.65%
Phosphorus (P)0.04% max
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

Minimum PropertiesUltimate Tensile Strength, psi78,300
Yield Strength, psi60,200
Rockwell HardnessB84
ChemistryIron (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%
Sulfur (S)0.26 - 0.35%


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

Minimum PropertiesUltimate Tensile Strength, psi43,900 - 51,900
Yield Strength, psi26,100 - 34,800
Elongation42 - 48%
ChemistryIron (Fe)99%
Carbon (C)0.08%
Manganese (Mn)0.6% max
Phosphorus (P)0.035% max
Copper (Cu)0.2% min
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

Minimum PropertiesUltimate Tensile Strength, psi87,000
Yield Strength, psi72,000
Rockwell HardnessB89
ChemistryIron (Fe)99.08 - 99.53%
Carbon (C)0.18 - 0.23%
Manganese (Mn)0.3 - 0.6%
Phosphorus (P)0.04% max
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

Minimum PropertiesTensile Strength, psi97,000
Yield, psi57,000
Brinell Hardness201
ChemistryCarbon (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%
Molybdenum (Mo)0.15 - 0.25% max