Skyjacker® Coil Springs are specifically designed to give the ultimate in quality, durability and dependability. Each coil spring design is individually engineered to coordinate with each vehicle’s suspension characteristics. Our springs are made from high quality 5160H chromium alloy and shot-peened to yield a higher tensile strength and longer life. The spring is then entirely compressed under hydraulic pressure to preset the coil which dramatically reduces any chance of fatigue or sag. Furthermore, a baked on powder coating is applied for continued protection against corrosion both on and off the road. Aside from these features, each coil spring design has endured a cycle test to assure the very best in quality.