Hook spring 1.material: carbon steel,stainless steel 2.Wire Diameter of latch spring: 0.20 mm to 3.2mm. 3.finish:zinc,yellow latch hook spring1.material: carbon steel,stainless steel2.Wire Diameter of latch spring: 0.20 mm to 3.2mm. 3.Surface Treatments of latch spring: Zinc Plating,Chrome Plating,Nickel Plating,etc. 4.Raw materials are stainless steel,music wire,carbon steel etc.5.Stabe,reliable ...