This specification covers the requirements for quenched and tempered alloy steel hexagon socket button (SBHCS) and flat countersunk (SFHCS) head cap screws having material properties for high-strength requirements. Materials shall be tested and shall conform to specified values of materials requirements; chemical composition; mechanical properties such as thread size, stress area, tensile strength, yield strength, elongation, and hardness (Rockwell C and Vickers DPH); and other requirements such as decarburization, and embrittlement. Workmanship, finish, and appearance are also detailed.