... Zero-defect,high quality 3. Fatigue test>5000000 Steel spring Detailed description: 1) Spring Wire Diameter: ... wire formed spring. 3) Main material: High carbon steel, spring steel, stainless steel, bronze, alloy4) Advantage: Good hardness, resistance, ... 15 days after receiving your payment.11) Application: Widely used in automobiles, motorcycles, electrical appliances, telecommunication, craft, toys ...