Single Lug Nut

A Single Lug Nut is a wheel fastening system that uses one central nut to secure a racing wheel to the car's axle, instead of the typical four or five lug nuts found on regular cars.

This system is also called a centerlock wheel system because the single nut sits in the center of the wheel. Think of it like a giant bolt that holds the entire wheel in place from the middle, rather than having multiple smaller bolts around the edges.

The main reason race teams use single lug nuts is speed. During a pit stop, mechanics can remove and install a wheel much faster when they only need to deal with one nut instead of five. In Formula 1, where pit stops can be completed in under three seconds, every fraction of a second counts.

Formula 1 cars are the most famous example of single lug nut systems. The pit crew uses special pneumatic wheel guns that can quickly spin the nut on or off with incredible precision. NASCAR's Next Gen cars also adopted this system to speed up their pit stops.

The single lug nut must be extremely strong since it's doing the job of multiple regular lug nuts. Race teams tighten these nuts to very high torque specifications using specialized equipment. The nut and wheel are designed to work together as a matched system.

While faster wheel changes are the biggest advantage, there are some drawbacks. If the single lug nut isn't properly tightened or if the equipment fails, the wheel can come loose - which is obviously dangerous. The specialized nuts and wheels are also much more expensive than standard multi-lug systems.

Most road cars don't use single lug nuts because they require expensive specialized equipment and training. However, some high-end sports cars do offer centerlock wheels as an option for track use.