... :ZW,ZB,ZY,Nickel, ZP.else 4)Tolerance:0.01 Spring washer1)Standards:DIN127A, DIN127B ASME B 18 21.1 BS ... ,copper3)Surface treatment:Polishing(plain),black,zinc plated (blue, white, yellow), hot dipped galvanized,trivalent zincZ/PCR3,Phosphating4)Packing:bulk in ... to customer's requirement.More than ten years' experience in spring washers and other fasteners.Sincerely welcome to contact us for ...