Home / Standards / GB/T 8731-2025 GB/T 8731-2025 Active Free-cutting structural steels 易切削结构钢 Standard Type GBT ICS 77.140.01 CCS H 40 Status 现行 Issue Date 2025-10-31 Implementation 2026-05-01 Responsible Dept 中国钢铁工业协会 Drafting Unit N/A