What is A449?

A449 is an ASTM specification covering “Hex cap screws, bolts and studs, steel, heat treated, 120/105/90 ksi minimum tensile strength, general use”. From ASTM: “This specification covers quenched and tempered steel hex cap screws, bolts, and studs having a minimum tensile strength. The fasteners are intended for general engineering use. Type 1 fasteners shall be plain carbon steel, carbon boron steel, alloy steel, or alloy boron steels conforming to the requirements. Type 3 fasteners shall be weathering steel and shall conform to one of the chemical compositions specified. Tensile strength, proof load, hardness tests, and axial tension tests shall be performed to conform to the specified requirements.”