... .8/10.9/12.9 4.case hardening:HRC38-HRC42 raw material40Cr,35CrMosize1/2''--1.1/4,M12--M36Colorblackgrade10.9/12.9handnessHRC35- ... weld nuts, square nuts, cap nuts.Washers: flat washers, spring washers, lock washers, structural Washers. square washer, bowl washer.Screws ... 2008 Olympic Games. We have five factories, one Export & Import Company and one Venture Capital enterprise. Our company was founded ...