hexagon socket countersunk screw: Hexagon socket countersunk screws Head cap screws Grade:10.9,12.9 Standard:DIN7991/ANSI B18.3 Surface hardness:HRC39-42 Surface treatment:black Packing:carton+wooden pallet Payment:T/T.Irrevocable L/C at sight,Western Union. Small order acceptable. We specialize in manufacturing kinds of special fasteners according to customer’s drawing or sample.Welcome to visit our factory.