Home / Standards / GB/T 974-1976 GB/T 974-1976 Active Screws，cross recessed，120° raised countersunkhead 十字槽120°半沉头螺钉 Standard Type GBT ICS 21.060.10 CCS J13 Status 现行 Issue Date 1976-10-13 Implementation 1977-10-01 Responsible Dept 中国机械工业联合会 Drafting Unit N/A