... Time:30 days 1. Standards:JIS SK5 ,DIN 1.1830,GB:T8Mn 2. Surface: Black surface/Turned/Ground3. Process: EAF ... +LF+VD+ Forged+ Heat Treatment (Annealed, Normalized, Q+T)4. Machine Capability Hardness:annealing, ≤187HB, indentation diameter≥4 ... good abrasion after heat treatmentNote: 1. According to national standard (GB)for our products, if not, supply according to national standards ...