1.1 This specification covers the requirements for quenched and tempered alloy steel hexagon socket button (SBHCS) 0.060 through 0.625 thread sizes and flat countersunk (SFHCS) 0.060 through 1.5 thread sizes head cap screws having materi This specification covers the requirements for quenched and tempered alloy steel hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws. The screws shall be fabricated from alloy steel made to fine grain practice. The chemical compo