Home / Standards / GB/T 39645-2020 GB/T 39645-2020 Active Technical drawings—Symbols for geometrical tolerancing proportions and dimensions 技术制图 几何公差符号的比例和尺寸 Standard Type GBT ICS 01.110 CCS J04 Status 现行 Issue Date 2020-12-14 Implementation 2021-04-01 Responsible Dept 国家标准委 Drafting Unit 国家标准委