... certification 4.material: stainless steel,carbon steel grade 12.9 mild steel hexagonal socket head cap screw 1 ... screw: plain, zinc Cr+3,Yellow Zinc Cr+6 5)Packing: bulk, box packing Material1.Stainless Steel: SS201 ... steel, brass Grade: 8.8,10.9,12.9,SAE J429 GR.5/GR.8 4.Surface of screw: Black ... etc. 5.Packing: bulk, box packing, polybag.6.we have passed ISO 9001:2008 certification grade 12.9 mild steel ...