Oxido Hex head with washer self tapping screw Flat head rivet for sealing good occasion. If hull, boiler, container, et Oxido Hex head with washer self tapping screwFinish:white zinc plated,color zinc plated ,nicklel plated Advantages:good quality,good service,timely delivery,competitive price,large production capacityWe can also supply according to buyer sample or drawing of picture