This specification covers an aircraft-quality, low-alloy steel in the form of sheet, strip, and plate.This product has been used typically for components requiring welding and moderate tensile properties, but usage is not limited to such applications. Product 0.125 inch (3.18 mm) and under in nominal thickness may be through-hardened to a minimum tensile strength of 180 ksi (1241 MPa); greater thickness will present proportionately lower strength.