1,OEM 2,Raw material: 40Cr. 35K 45# 3,certificate: ISO9001-2008 4,Surface: plain, Zinc,HDG,Dacromet 5,Size:Dia from 16 ... in free fit or wrench fit threads.Available in size 5/8", 13/16", 7/8", 15/16", 1", 1-1 ... : Nuture, black, pot galvanizing, cold galvanizing, oil, parkerising etc.2. Grade: 5.6, 8.8, 10.6 and12.93. Dia: from M16 ...