1. material :spring steel,65Mn,stainless steel 2. surface: zinc,black,dacromet,geomet 3. completion : pressing 1.. Material: stainless steel, iron, copper, aluminum, carbon steel2.hardness:HV300-5003.heat treatment:HRC40-504. Item name: clip from china5. Surface treatment: nickel, white zinc, blue zinc, color zinc, yellow zinc, black zinc, chrome6. Have high strength of the rib tighten role, ...