... .8 8.8 carbon steel hex hd bolt black 2. Stainless stell hex head bolt DIN931/DIN933 The main products are ... stainless steel hex head bolts, hexagon socket setscrews, machine screws, expansion ... the drawing samples given by customers. The main material : 1. stainless steel : SS304 SS316 201 667 668 2. carbon steel ( Iron ...