มอก. 675-2530

Scope (English)

Specifies bottom bracket shells for bicycles of 21 and 22 nominal sizes. Prescribes dimensions and tolerances, threads, property of steel pipes used (e.g. tensile strength, elongation), surface shells, rectangularity of seat tube and down tube along the plane of bracket shells. Includes marking, labelling, sampling and criteria for conformity, testing.