... :ISO9001 5.OEM 's accept We are professional spring manufacturer, have over 20 years experience in spring production and ... 15-8mm12Material:carbon steel,stainless steel, manganese steel wire, nickel wire, galvanized wire,alloys,etc13Casting experience:More than 20 years14Strong technology ... outside diameter, minimum inside diameter(5) Number of coils Manufacturer supplied round wire shaped snap ring