标准号:IS 3121-1981
发布日期:1982/9/1 12:00:00
实施日期:1999/12/31 12:00:00
适用范围:Specifies materials, components, dimensions, finishing and tests for rigging screws and stretching screws ( double-ended and single-ended ), of the following nominal sizes:a) Rigging screws: M12 to M90, andb) Stretching screws: M6 to M52.