Lug Nut Types and Sizes

You’ve probably heard of lug nuts, but what do they do? Lug nuts, or lug bolts, are the hardware that is used to secure your wheels and tires to your vehicle. Having the correct lug nut for your vehicle helps ensure that your wheel is safely and securely installed. Here’s a rundown of lug nut types and sizes.

Lug Nut Types

Conical or Tapered Seat
cone-shaped lug seat

Spherical or Ball Seat
rounded lug seat

Mag Seat
extended thread area
and a flat washer seat

Flat Seat
flat, washer-like seat

Extended Thread (ET)
conical shaped seat
with an extended thread
for more thread engagement

Tuner Style
small diameter using
a special key on the
outside end with a conical seat

Small Diameter Spline Drive
small diameter using a
special key on the spline grooves
with a conical seat


Lug Bolts - lug nuts with the stud attached and used on vehicles that have a flat rotor with no studs

Lug bolts are essentially lug nuts that have the stud attached to them. They are typically seen on European vehicles, such as Audi, BMW, Mercedes, and VW. When installing lug bolts, it is important to ensure that they are not too long for the wheel which can cause movement issues. Check that the lug bolts are not too long by spinning the wheel while it’s off the ground, making sure it has 360-degrees of motion.


Lug Nut Sizes

Lug nut sizes have a specific thread pitch, which is determined by vehicle specifications. It is important to match up the lug nut to your specific vehicle.

  • 10mm X 1.25
  • 12mm X 1.25
  • 12mm X 1.50
  • 12mm X 1.75
  • 14mm X 1.25
  • 14mm X 1.5
  • 14mm X 2.0
  • 7/16" X 20
  • 1/2" X 20
  • 9/16" X 18

Note: Most lug nuts are right-hand threaded. Left-handed threaded lug nuts are not very common and would have a "L" or "LHT" stamped on the side of the lug nut.

It is crucial that the lug nut seat and the wheel lug seat match. If the lug nut seat type does not match the wheel seat type, it is possible that the lug nut could damage the wheel. It is also likely that a mismatched lug nut and wheel could potentially cause the lug nut to loosen and the wheel to become unsecure to the vehicle.

Aftermarket Wheels and Lug Nuts

Aftermarket wheels, wheels that did not come original equipment (OE) on your vehicle, are designed to upgrade the appearance and even performance of your vehicle. If you get aftermarket wheels, make sure you have lug nuts that will fit properly. Most OE lug nuts are not designed to fit aftermarket wheels. That’s why we recommend purchasing a wheel installation kit to ensure the lug nuts match your wheels.

Proper Lug Nut Thread Engagement

Thread engagement refers to how much of the stud the lug nut contacts. For your safety, proper thread engagement must be met.

If proper thread engagement cannot be met with a standard lug nut, an extended thread (ET) lug nut may be necessary. When installing an ET lug nut, you must ensure that the lug holes in the wheel are wide enough to accommodate the ET lug nut. If the lug nut isn’t long enough to engage the threads, the wheel will not be secured properly.

Proper Lug Nut Torque

It is very important to make sure the lug nut is torqued to the right specifications. If overtightened, both the lug nut and the stud can be fatigued, possibly leading to failure. To learn about the proper torque settings for your vehicle, check out our wheel torque chart.

Outside Diameter of Lug Nuts

It’s important to be aware of the lug head diameter.

Some lug nuts have a hex nut shape that is designed for a range of regular sockets. Others have a spline-like shape that requires a special key. There are also locking lug nuts, which require a serial-numbered lug key for install/removal.

If you purchase aftermarket lug nuts, make sure that you have the hardware to be able to install/remove your lug nuts. It may be a good idea to invest in a universal tire iron.

Small diameter lug nuts are commonly used on aftermarket wheels and will require an adapter for install/removal. This adapter may not be the same size as the OE lug head diameter.

Have any more questions about lug nuts? Please, give us a call.