Home / Standards / GB/T 3670-2021 GB/T 3670-2021 Active Covered electordes for manual metal arc welding of copper and copper alloys 铜及铜合金焊条 Standard Type GBT ICS 25.160.20 CCS J33 Status 现行 Issue Date 2021-12-31 Implementation 2022-07-01 Responsible Dept 国家标准委 Drafting Unit 国家标准委