มอก. 690-2530

Scope (English)

Covers inlet and exhaust valves with heads of not exceeding 75 mm diamaters. Specifies dimensions nad tolerances, chemical composition and mechanical properties of materials, appearance, surface roughness, tip hardness, cylindricality, roundness, straightness of shaft, face run-out, ractangularity of head and of tip, eccentricity of groove. Includes packaging, marking, labelling, sampling and criteria for conformity, testing.