Home / Standards / GB/T 152.4-1988 GB/T 152.4-1988 Active Fasteners--Counterbores for hexagonbolts and nuts 紧固件 六角头螺栓和六角螺母用沉孔 Standard Type GBT ICS 21.060 CCS J13 Status 现行 Issue Date 1988-02-06 Implementation 1989-01-01 Responsible Dept 中国机械工业联合会 Drafting Unit N/A