Car & Truck Wheel Nuts, Bolts & Studs

Car and Truck Wheel Lugs

If you replace the rims on your car or truck, you may also need to replace the wheel lug nuts. Choosing the right wheel lug nut is vital for the safe operation of the vehicle.

Lug nuts and studs are the parts that keep the wheels securely fastened to your car. The studs are long, threaded bolts that extend from the hub of the axle. When the wheel is seated on the hub, the lug nuts are screwed onto the studs.

Your vehicle has a bolt pattern that is expressed with two numbers. For example, a common bolt pattern for a car is 5x100. The first number is the number of studs on each wheel. This number can be as low as three for small cars or as high as eight for heavy vehicles.

The second number is the diameter of the circle formed by the studs. This may be expressed in inches or millimeters. A 5x100 pattern means the five wheel studs form a circle 100 millimeters in diameter.

There are seven different styles of lug nut. The main difference between them is the portion of the nut that tightens against the wheel stud, called the seat. It is crucial that the seats on the lug nuts and the wheel match to keep the nuts from working loose.

• Conical or tapered seat: This type is a hex nut with a short, tapered seat. It is a style seen in many vehicles.
• Spherical or ball seat: This is a hex nut with a rounded seat.
• Mag seat: The mag type is an extended hex nut with a flat, washer-like seat.
• Flat seat: This type is like the mag seat, but without the extended portion.
• Extended thread: This type is essentially a conical nut with a slightly longer section for engagement.
• Tuner style: The tuner lug nut is a smooth cylinder with a tapered seat.
• Spline drive: This style has narrow grooves on the outside. They require a special tool called a key to tighten them. Spline drive nuts have a tapered seat.

Also called wheel locks, these devices require a special key that comes with the set of locks. You can use one lock per rim or replace every lug nut on each wheel with the locking type. Using these lug nuts will keep unique rims secure, as well as deter their theft.