1.1 This specification covers the requirements for quenched and tempered alloy steel hexagon socket-head cap screws, 1.6 mm through 48 mm in diameter having a minimum ultimate tensile strength of 1220 MPa. 1.2 The values This specification covers the requirements for quenched and tempered alloy steel socket-head cap screws. The screws shall be fabricated from steel made to fine grain practice and shall be alloy steel conforming to the chemical composition specified. Di