Product name: Spring Material: Stainless steel, alloy steel, carbon steel. Aluminum, copper, iron Q235, 45#steel, 40Cr, 35CrMo, 42CrMo. C20, SS304, SS316 Unit Weight: 0.05kg-20kg, 0.1lbs-40lbs Size scope: 50~1000mm, 2~40 inch Customizable or not: Yes Certificate: ISO9001:2008 Inspection report: Dimension report. Material report including chemical contents, tensile strength, yield strength and hardness. X-ray test report, Ultrasonic test report and Magnetic particle test available upon request. Origin: China