Home / Standards / GB/T 6728-2017 GB/T 6728-2017 Abolished Cold forming hollow sectional steel for general structure 结构用冷弯空心型钢 Standard Type GBT ICS 77.140.70 CCS H44 Status 废止 Issue Date 2017-07-12 Implementation 2018-04-01 Responsible Dept 中国钢铁工业协会 Drafting Unit 中国钢铁工业协会