... raw material40Cr,35CrMosize1/2''--1.1/4,M12--M36Colorblackgrade10.9/12.9handnessHRC35-42(BOLT),HRC29-36(NUT)surface treatmentflange/phosphatetechnologyforging+thermal ... eye bolts, U bolts, masonry bolts, roofing bolts.Nuts: spring nuts, T nuts, K nuts, rivet nuts, cage nuts ... nuts, square nuts, cap nuts.Washers: flat washers, spring washers, lock washers, structural Washers. square washer, bowl washer ...