1. Name of commodity: Precision Hardware Spring (QL-S-001); Product Keywords: Coil spring; Flat spring; Machined spring; Extension spring; Compression spring; Torsion spring; Cantilever spring; Blance spring; Leaf spring; V-spring; Belleville spring; Constant-force spring; Gas spring; Main spring; Negator spring; Progressive rate spring; Spring washer; Wave spring. 2. Material: Spring metal, low carbon steel, ss304, ss301, 65mn, 16mn 3. Surface process: Zinc plated, powder coated, painted, polishing 4. Weight: From 5 grams to 3000 grams 5. Spring thread dimensions: Can be 3mm to 8mm. We have over 7 years of producting experience of metal spring product. They are widely used in machinery assembly, agriculture machinery fittings, holding and lifting system parts, furniture hardware and fiitings. As per customers' requirements!