Once you have made a wheel sale, test-fitted the wheels, and mounted and balanced the tires, you must do one final thing--attach the wheels to the car. Although often overlooked, the hardware associated with wheels is vital to getting a good installation.

The most obvious piece of hardware is the lug nuts used to secure the wheel to the car. In most cases, either for appearance sake or functionality, you won't use the stock lug nuts to attach the wheels. Lug nuts come in three broad categories: acorn, mag and tuner style. Within each category, there are a number of variations. Some European cars use a fourth type--a lug bolt which screws into the vehicle. A typical catalog shows nine acorn styles, three mag styles and five tuner styles.

Fortunately, the wheel catalog will usually tell you which type of lug nuts to use with the wheel you are buying and of the 17 styles mentioned above, a few are pretty rare. It's a good idea to have the more common styles in stock to prevent any delays when installing wheels.

Acorn styles are the most common and they are available in either open end design, which are used when the lug nuts are covered by the wheel's center cap, or closed end type, which are used when the lug nuts are exposed. Closed end designs come in various lengths, the longer ones normally used on trucks where extra length is needed.

Mag styles are the least common, used mainly on older style wheels. Mag lug nuts must be used with washers.

Tuner style lug nuts are used where there is very little room in the lug nut opening. This is especially common on small, front wheel drive cars known as "tuners." That's where the name comes from. They come with a "key," which either fits into a cut out in the center of the lug nut or goes over the lug nut itself. Without the key, you can't remove the lug nut, so make sure you give this to your customer.