Lug nuts are extremely important to the safety of your vehicle. Although they may be small, these screws are essential to the integrity of the fastening system and needed to properly secure the wheel to the hub. If lug nuts are not fixed on right, the entire wheel installation process is at risk.
A lug nut that is not tight enough will eventually loosen, resulting in damage to the wheel or separation from the vehicle. One that is fastened too tightly can possibly crack during an installation. Lug nuts are designed to have some elasticity; with wheel studs and nuts, the slight stretch allows for the correct preload necessary to safely and securely buckle the wheel to the hub. However, the stretch does not prevent a lug nut from being screwed beyond the specification, and a wheel stud or bolt can be permanently stretched if over twisted.
Loose lug nuts are often caused by a lazy application, and over-tightened lug nuts can be the result of using too much force with an impact gun or other piece of equipment. Custom wheels should never be installed using an impact gun – they are difficult to control, don’t allow you to master the tightness, and can easily damage the lug nut or surrounding rim.
So, how do you make certain that the clamping loads meet the specifications? Good, old-fashioned handy work. A high quality, properly calibrated torque wrench and some dedication to tightening the lug nuts is the best way you can ensure that the job will be completed to standards.