Home / Standards / GB/T 45781-2025 GB/T 45781-2025 Active Seamless steel tubes for mechanical structures 结构用机加工无缝钢管 Standard Type GBT ICS 77.140.75 CCS H 48 Status 现行 Issue Date 2025-06-30 Implementation 2026-01-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A