What is a Lug Bolt?

A lug bolt is a solid threaded rod with a cone-shaped end that is typically mounted into a wheel hub on an axle of a vehicle. Once the bolt is attached to a wheel hub, the tapered end protruding from the axle can receive a lug nut for fastening. The primary purpose of lug bolts is to support wheels on vehicles.

Many vehicles have different wheel patterns. A lug bolt pattern is the design on a wheel that accounts for the distance between bolts and number of bolts on an axle. These lug bolt patterns come is many sizes and dimensions depending on the usage of the vehicles, but typically range in four, five, or six bolt patterns.

The lug bolt pattern can be determined by measuring the distance between the lug bolts on the axle. This measurement procedure is unique for each wheel pattern. Even patterns can be measured by determining the distance between opposing lug bolts, whereas odd patterns require a more complex measurement scheme.

The most dominant wheel lug bolt pattern in cars is the four and five bolt pattern. This dominant pattern has made for the mass production of universal wheels prevalent in the market place. While wheels with larger bolt patterns are available, they typically require special ordering.

In racing applications, most wheel patterns fall into the five and six lug bolt pattern design. This gives more support and overall displacement on the axle when the wheel is tightened with the lug nuts. In general, the more lug bolts and evenly dispersed a lug bolt pattern, the better a wheel will handle.

Heavy trucks and off-road trucks have an even greater need for additional bolts due to the extra stress the vehicles put on their axles. These implementations can range from six to nine bolts. The lug bolt pattern is evenly spread around the center of the axle to ensure overall stability.

Lug bolts come in many shapes and sizes depending on their usage. They are all made of metal, but come in many colors. Show cars and many auto enthusiasts have replaced the metal look of typical lug bolts with chrome bolts.

Installing a lug bolt into a wheel hub requires a piece of special equipment. This is known as a wheel hub lug bolt tool and is used for both the insertion and the removal of lug bolts. This tool compresses a lug bolt into a wheel hub to ensure that it is securely implanted into an axle.