... washer , plain washer , steel carbon washer , zinc plated washer , black washer , by sea , 8.8, 4.8 , box in carton , bulk ... size:all size4.surface: zinc plated , plain ,black , H.D.G ,5.transportation:by sea6.packing:bulk , box in carton , ... aluminum, brass or other special materials. For finishing, we provide black oxide, zinc electroplating, phosphate, copper plating, mechanical galvanization, hot ...