Proper suspension design starts with an understanding of the automotive enthusiast's needs. These needs are considered by H&R engineers and are integrated into the design of every spring set.

Prototype spring sets are developed and are subjected to grueling test sessions where the chassis dynamics are analyzed. Key elements involved in development included ride height and spring rate, which are dictated by the handling characteristics of a stock chassis, stock suspension limitations, as well as tire and fender well clearance. When a design has been finalized, the manufacturing planning process begins. Manufacturing high quality automotive springs can only be achieved with true understanding of the correct metal alloy wire and spring wire resilience.

H&R Springs only use superior quality steel wire from the precision mills Thyssen, DWK, and Krupp Steel Works in Germany. This special spring steel is used exclusively as the service life is longer than any other wire tested. If you compare wire material alone, other spring manufacturer's wire would not come close to the quality of H&R wire alloy.

All H&R Springs are cold wound on precision Wafios CNC spring coiler machinery. After the coiling and cutting process, the springs are heat-treated. This heat treating is very important since the spring is wound from a one ton ring of heat treated wire stock that is about three meters in diameter, and then formed into a small coil spring. The winding process creates heat and stress spikes between the molecules of the wire. The stressed molecule spikes must be realigned within two hours (or the springs lose their resilience.) H&R's manufacturing is distinguished from the competitor's practice because H&R springs receive secondary heat treating / annealing immediately.

After tempering, applications that require a flat surface go to grinding.

Next, the springs are shot peened. Shot peening is a process that works on the thin surface layer. The spring surface is blasted with metal shot moving at very high speed. This blasting action of the shot removes surface imperfections and relieves internal stresses. This shot peening technique is only useful if the blasting action is directed to the area of the highest stress, which is the inside of a coil spring. So important is the shot peening for a cold wound coil spring that service life is extended by more than 200%. Only the finest quality spring manufacturers automatically shot-peen their spring products.

The next step is pre-setting the spring. Pre-setting is when the spring is completely set to block. This is where the spring is compressed so all the coils are touching. This gives the spring a permanent set and guarantees that the spring will not sag during its service life. A pre-set spring can also be referred to as a block resistance spring. In production, a spring is actually made to a longer free length than required because the spring gets shorter during the setting process, thus bringing it down to the design specifications. All H&R Springs are pre-set using an exclusive Super Blok spring setting procedure. The springs are set 4 times to a specific time duration. Some manufacturers do not set their springs, or if they do, they set them only once. There are more springs on the market today that are not "block resistant," than ARE "block resistant." After setting, the springs are 100% tested on an exclusive H&R designed tester for ride-height and spring-rate according to design specifications. This is the final step before coating. H&R Springs utilize intensive quality standards for spring deflection testing, surpassing all industry and government standards.

Now the springs are ready for the coating procedure. H&R has developed a unique state-of-the-art, comprehensive finishing system. The springs are hung on a conveyer track from start-to-finish. When the spring is placed on the hook it becomes electrolytic charged and attracts opposite charged cleansing and coating particles. First, the springs are cleaned and degreased with a non-aggressive alkaline solution. Then a zinc-phosphate coating is applied as a base for the paint. While still on conveyer, the spring is dried. From the drying cycle the spring goes directly to the spray booth. The opposed charged polyurethane epoxy powder coating is manually applied. Only in this manner can a coating thickness of 30 - 50mm be guaranteed. In the case of automated spray booths, irregular coating thicknesses from inside to the outside of the spring are common. A coating that is too thick tends to result in cracks in the coating during motion and could cause corrosion.

The spring travels to the oven and cured at a temperature between +374 degrees F and +392 degrees F. Temperature is critical because if it's too low the powder coating will not cure properly. Temperatures that are too high will reduce the shot peening effect. When the springs move out of the curing oven they are removed from the conveyor track, and the spot where the hook was holding the spring is painted by hand. The spring is now completely protected from the elements. No spring manufacturer does this last, very detailed step. Springs finished with this coating procedure can resist corrosion in a salt spray test in excess of 500 hours without any blemish to the coating. The salt spray test is where a warm salt slurry solution is sprayed at a constant pressure onto the spring to check corrosion resistance.

The springs are now stamped with designation marks to identify them. The finished product is now carefully packaged into specially engineered containers(to prevent transit damage) for shipment to us. H&R is proud of each and every spring because they will always be manufactured with careful attention to design and quality control. As one of the largest distributors of H&R products in North America, AWE Tuning is proud to recommend this product to every discerning driver.

We hope that this was informative! When you purchase an H&R Spring, you are buying the highest quality spring available - Springs that have been engineered for the enthusiast to deliver the best performance driving feel without sacrificing ride quality. Please click here to return to the H&R Gallery main page.