This specification supplies engineers and designers with: 1) poppet valve nomenclature; 2) poppet valve alloy designations; 3) chemical compositions of poppet valve alloys; 4) a guide to alloy metallurgy and heat treatments; 5) general information on properties of valve alloys; 6) a guide to the applications of alloys; 7) a description of valve design and construction, and their relation to valve alloy selection; and 8) valve gear design considerations that affect valves.