... of the product: all sizesurface of the product: yellow zinc plated , zinc plated , black , plain , H.G.Dpacking of the product ... special materials. For finishing, we provide black oxide, zinc electroplating, phosphate, copper plating, mechanical galvanization, hot dip ... or upon our customers' special requirements, in grades 4.8, 6.8, 8.8, 10.9, 12 ... visit us. hexagon bolt DIN933 yellow zinc plated