มอก. 669-2530

Scope (English)

Covers cross-recessed head tapping screws made of cold heading, case hardening quality steel. Classifies the tapping screws into 3 classes according to the shapes of threaded part as type C-cone end and type F-flat end. Specifies shapes, dimensions and tolerances, surface hardness, case depth, core hardness, microstructure, thread-forming capacity, torsional strength. Includes packaging, marking, labelling, sampling and criteria for conformity, testing.