sem screw with washer

1.Material:steel,stainless steel,brass,copper,and other alloy 2.Plating:zinc plating,nickle plating,dacro coating,silver plating,gold plating,tin plating,chrome plating 3.heat treatment: according to the customer's request,can reach class8.8,class10.9,class12.9 4.thread type:machine screw,selp-tapping screw,triangle thread tapping screw,wood screw,drywall screw,chipboard screw,hex head bolt,and special customer-made thread type 5.salt-spray test: according to the customer's request and the longgest time can reach 1000 hours