How Sway Bars Are Made
Manufacturing a sway bar has been done by various methods throughout the years. The traditional method of making a bar is to take the raw bar stock, and bend it into the shape you want by using a press and bend dies. This is generally a cheap way to make them, and there are several drawbacks to this method. The first such detriment is that each bend is done separately. With each bend the tolerance increases, i.e. inaccuracy, in making the part. This allows for increased human error in production. As trucks become more complex, the packaging of the sway bar tightens. There is less room for error, and thus the part needs to be more accurate to fit in the car. Another disadvantage is that the press bends can add several extreme tooling dents or "marks" to the product. Dents such as these are acceptable on a solid bar, but they make the part less pleasing to look at. Tubular material cannot be bent in this traditional way. The press will either kink or crack the tubing when bending the material.

Companies like Hotchkis use CNC (Computer Numerically Controlled) bending machines and tubular stock. The CNC does all of the bends in one handling process. Raw material is loaded into the machine, which then goes through a series of motions to produce a smoothly bent part. A computer keeps track of each bend in relation to all of the other bends. This produces a very high-tolerance part, typically in the 0.050-inch range or tighter, and with consistent reliability. During the manufacturing run, a Laser Vector inspection system is employed to measure the parts being bent by the machine. This measures the shape of the bar, and compares it to a computer file of the part print. The laser's computer sends any necessary corrections directly to the bending computer. This is done because each batch of raw material varies and bends slightly different than another.

Like all aftermarket products, sway bar testing procedures can vary from company to company. Some of the lower-end products are simply upsized versions of factory parts with increased rates and are not tested at all. The more high-end components like those manufactured by Hotchkis are rigorously tested at the track and on the street for the optimal balance of handling improvement, driver feedback, adjustability, and ride compliance. John Hotchkis states that his company's tests use a 200-foot skid pad, 600-foot slalom, road course, and street drive tests to ensure every system works correctly.

In conclusion, a well-designed, lighter tubular sway bar package is the best handling benefit you can bolt on to your classic truck. The next step in the bolt-on handling equation is a set of premium shocks. These will make a world of difference and improve overall suspension performance and ride quality.