Home / Standards / GB/T 21947-2008 GB/T 21947-2008 Active Numerically milling machines for special screws - Testing of the accuracy 数控异型螺杆铣床 精度检验 Standard Type GBT ICS 25.040.20 CCS J56 Status 现行 Issue Date 2008-06-03 Implementation 2009-01-01 Responsible Dept 中国机械工业联合会 Drafting Unit 中国机械工业联合会