All DURA-LIFT torsion springs are manufactured from Class 2 high-tensile, oil-tempered spring wire, meeting ASTM A229. All of our torsion spring wire is coated for improved corrosion resistance and easier handling. Both 10,000 "standard" cycle and 25,000 "high-cycle" springs are available in left or right wind, and in precut or longer lengths. Both the winding and stationary cones are professionally installed for safe operation. Two 12-inch winding rods are included with all orders. Torsion springs are designed to lift specific weights and should be replaced with springs of the same size and wire gauge. Make sure to correctly determine your wire gauge, inner diameter, and length over coils.