While attending last year's Essen Motor Show (et 3/08), we didn't want to waste our limited time in Europe drinking pils and stuffing ourselves with schnitzel (that's not entirely true -Ed), so we coordinated an exclusive tour to go behind the scenes of the H&R Springs manufacturing facility. The plant sits 150km (90 miles) northwest of Frankfurt and employs more than 100 people, from engineers and factory workers to customer service representatives.
So why, of all the things to see in Germany, would we visit H&R? Well, there are four good reasons. The first is that aftermarket suspension products are possibly the most commonly used parts in the European car industry. Chances are, your car's lowered and we all know how good suspension improves not only handling but also the look of your car.
The second reason is H&R's huge product and application range. If you drive a European car, H&R has a product for it. And the range includes springs, shocks, coilovers, sway bars, spacers and wheel adapters.
Thirdly, H&R has a strong motorsport presence. They've worked with teams in F1, WRC and DTM, among others, to design specific components such as aluminum springs.
Finally, H&R claims to be the first company to introduce an aftermarket performance spring to Europe and to be the originator of the full-bodied coilover suspension. And because they were the first, they have a status to uphold so use the latest technology to produce the best parts and devise the most stringent testing.
Assembly Line:Prototyping & TestingBefore any part is manufactured, H&R obtains the chosen car to determine the amount of suspension tuning it needs, such as ride height adjustment and spring rate. It has an in-house installation facility, along with experts who determine the specifications of each part. In the case of US-specific cars, H&R does its research in its Bellingham, WA facility and sends the information back to Germany for production.
Once a prototype is made, the products are tested in the real world. They use the multitude of twisty country roads around the little town of Lennestadt, Germany, as well as the nearby autobahn and the Nrburgring, which is less than two hours away.
Cold WoundThe biggest single item of production and sales is coil springs. You can choose from a set of lowering springs or have them included in a suspension kit with dampers, such as the Cup Kits and coilovers.
H&R uses highest quality 54SiCr6 steel wire, giving its springs less weight and a smaller diameter than other springs on the market.
A large section of the company's main building holds hundreds of various-sized wire coils, which can be selected for production. The wire is fed through a computerized CNC spring coiler, which is programmed to determine the spring tension, length and diameter. After the computer is set, the coiler takes mere seconds to create the desired spring. Each spring is then collected for inspection.
Heat-TreatedThe next process involves heat-treatment for the springs. This step must be done within two hours of the spring being wound and cut or it will lose its strength. Because the springs are shaped by intensive winding and are made from untempered wire, the process creates heat and stress spikes within the molecules of the spring. Therefore, the molecules must be realigned through heat-treating in order to maintain the best quality. Here you can see oil-quenched springs being treated as they move from oven to oven.
Shot-PeenedAfter heat-treating, the springs are shot-peened to ensure endurance and strength. During this process, the spring surface is blasted with metal shot. The quick-blasting smooths the surface of the spring, relieves internal stress and is said to extend the life of a spring by more than 200% compared to a spring that isn't shot-peened.