
Custom Stainless Steel Black Galvanize Coil Extension Spring. Custom Surface Treatment: Offers customized surface treatments including plating and powder-coating. Comprehensive Material Range: Available in Stainless steel, Carbon steel, Music wire, Brass, and Alloy steel. High Production Capacity: Weekly supply capacity ranges from 7,000,000 to 9,000,000 pieces. OEM and ODM Services: Provides full customization from samples, designs, or client ideas. Free Sample Availability: Free samples are available upon request for product evaluation. Advanced Testing Equipment: Equipped with digital hardness, torsion strength, and salt spray testers. Shot Peening Process: Shot peening applied to increase fatigue life and durability. 100% Final Inspection: All finished products undergo visual and functional inspection.