... 3Surface:Black,Zinc,Dacro 4Certificate:ISO9 Different types of grade 8.8 bolt specification Details of the product:1Materials: 1045, 45#, 40Cr, 35CrMoA ... , ASTM, GOST, JIS, AS, etc. 4Grade: 8.8 (4.6, 5.6, 10.9, 12.9, etc.) 5Surface: Black, Zinc-plated ... certified by ISO9001:2008 Quality Management System and got the Production Permission License from the Ministry of Railways, P.R.China. 2 ...