... ). Standard: (3). Grade:10.9(4). Size: M6-M36(5). Material: Carbon Steel(6). Surface treatment: Black oxidePhotos for detail Photos ... ,8.8,10.9,12.9 and others you needMaterial45#, 40Cr, 35CrMoA, 42CrMoA, 25Cr2MoVA, 35VB, 40CrNiMo,Stainless steel and so onSizeM6 ... 5) Prompt Delivery6) We have 10years experience of manufacturing fasteners 40Cr MATERIAL FITTING BOLT