Commercial

Definition - Hot rolled commercial quality steel is ordinarily produced in a low carbon grade of steel. It is suitable for many applications where the presence of oxide and normal surface defects are not objectionable.

Specification - Commercial quality steel is ordered to meet ASTM A1011 CS Type B requirements. For complete chemical and mechanical properties the Annual Book of ASTM Standards can be referenced.

Chemical/Mechanical Requirements - Commercial quality steel is manufactured to a carbon range of 0.02 to 0.15% carbon content and has no mandatory mechanical properties.

Structural

Definition - Structural steel is steel construction material, a profile, formed with a specific share or cross section and certain standards of chemical composition and mechanical properties.

Specification - Structural steel is ordered to meet ASTM A36 requirements. For complete chemical and mechanical properties, the Annual Book of ASTM Standards can be referenced.

Chemical/Mechanical Requirements - Structural steel has few chemical restrictions and is manufactured to meet a minimum 36 ksi yield strength.

High Strength

Definition - High strength steel meets the industry defined standard for high-strength low-alloy (HSLA) steel which is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel.

Specification - High strength steel is ordered to meet ASTM A1011 HSLA Grade 50 requirements for sheet thicknesses and ASTM A572 Grade 50 requirements for plate thicknesses.

Chemical/Mechanical Requirements - High strength steel is manufactured to meet specific limitations and/or combinations of the alloying elements defined to give the steel its environmental and mechanical properties. It has a minimum yield strength requirement of 50 ksi.