A36 Steel Specifications

Chemical Requirements

• A36 steel must meet certain chemical requirements. Certain elements can not be present in more than certain amounts, which may vary according to the thickness of the steel. All figures are maximums. A36 may not contain more than the stated amount of each impurity as a percentage of weight: Carbon, 0.29 percent; Phosphorous, 0.04 percent; Manganese, 1.2 percent; Sulfur, 0.05 percent; Silicon, 0.4 percent.

Strength

• In order to meet ASTM standards for A36 grade, a steel must meet certain strength requirements. Tensile strength, which refers to the amount of force needed to pull apart a slab of A36, must be between 56,000ksi and 80,000ksi, where ksi refers to kilopounds per square inch, a unit of stress used by ASTM to classify materials. Yield strength, which refers to the steel's ability to resist crushing, must be at least 36,000ksi.

Elongation

• Elongation is a property that refers to the ability of a material to stretch before breaking. A36 steel, as a low-carbon steel must exhibit a high degree of elongation. Test standards set by ASTM use two different thicknesses of steel. The steel must stretch a certain amount in order to meet the standard; elongation is measured as percentage of the original length of the piece being tested; for the 2-inch test, elongation must be at least 20 percent, for the 8-inch test, it must be at least 23 percent.