You might think that lug nuts are lug nuts. The reality is that there are a lot of different lug nut types. You can’t just toss a set of OE-style acorn nuts on a set of Cragars and expect them to stay on the car.

Most OEM lug nuts are not designed to work with aftermarket wheels.

close up of lug nuts on a custom wheel
These are OEM style open acorn lug nuts. Notice the tapered seat on the wheel. (Image/Jefferson Bryant)

Replacing the lug nuts on OE wheels is not a bad idea either—especially if you drive a GM product with those terrible capped lug nuts. These have with a chrome cap made of thin steel that have a bad habit of swelling and stripping off the lug nut itself. That makes them very difficult to remove, especially on the side of the road.

close up of lug nuts on a custom foose wheel
Aftermarket wheels can have very tight lug holes. You may need special lug nut sockets to install and remove these lug nuts. (Image/Jefferson Bryant)

Understanding Different Lug Nut Styles

The most important question is “what type of lug nut do my wheels require?”

The three most common types are cone (also called acorn nuts), shank (also called mag nuts), and lug bolts.

  1. Cone lug nuts are the most common type. They have a conical head on the wheel side of the nut with a taper that mates to the tapered flange on the wheel. The cone centers the wheel to the hub when you tighten the nut. This ensures that the wheel is mounted correctly and isn’t offset to the centerline of the hub.
  2. Shank lug nuts have a long shaft that goes inside the wheel flange. Instead of a cone, the shank centers the wheel to the hub. Shank lug nuts require a special washer, which usually has an inner and outer side that must be oriented correctly. There are various shank lengths to match the wheels you use. Don’t assume all shank-style lug nuts are the same, even if they are the same thread.
  3. Lug bolts are technically not nuts. They are wheel lugs that thread into the wheel hub and center the wheel like a cone or acorn nut. Lug bolts were popular prior to the 1960s and are still used on some European cars.

There are other, less common styles of lug nuts as well:

  • Ball seat lug nuts are found on Porsche and Volkswagen vehicles as well as some Honda and Audi vehicles. They have wide rounded ball flange that centers the wheel to the hub. They DO NOT interchange with cone nuts.
  • Flat seat lug nuts have no shank or cone, just a flat flange head with a washer. These can be found on some Ford trucks.
  • Extended thread lug nuts are mainly for specialty aftermarket wheels that require an extended-thread nut. They have a short shank of threads with conical taper on the outside.
  • Knock-offs are technically more of a retainer than a lug nut. They are a large single spinner on the hub that is “knocked off” with a wood, lead, or rubber mallet. Vintage British sports cars and C2 Corvettes use knock-offs instead of lug nuts.
close up of a knock-off wheel on a vintage car
The spinner on this crusty 1967 MGB GT wheel looks like an ordinary spinner-style cap, but the wheel is actually a real knock-off. (Image/Jefferson Bryant)
close up of a knock-off wheel threaded axle hub
This is the splined hub that engages the knockoff wheel. There are adapters available to convert standard hubs to knock-off style wheels. (Image/Jefferson Bryant)

Determining Proper Lug Nut Size

There is no universal size for wheel lug threads. You need to verify the lug threads on your vehicle before you buy new lug nuts. You can do that with a thread pitch gauge. Sometimes the thread is noted on the lug nut itself, but don’t count on it.

Most vehicles made after the mid-1990s use metric threads. Upgrading to aftermarket brakes and axles can change that. In fact, any axle, wheel hub, or brake rotor upgrade can change lug thread pitch and diameter. It is not uncommon for a builder to use a front disc brake conversion that requires metric 12mm x 1.75 lug nuts while the rears retain the OEM 7/16″-20 nuts. That means you need to buy two different sizes.

short shank lug nut diagram
This diagram from McGard shows how shank lug nuts are measured. (Image/McGard)

Most lug nuts are fine thread. SAE threads are typically 7/16″-20, 1/2″-20, or 9/16″-18. Metric fasteners have multiple thread pitch options, so you have to pay attention. Common metric lug nut sizes are:

  • 10mm X 1.25
  • 12mm X 1.25
  • 12mm X 1.50
  • 12mm X 1.75
  • 14mm X 1.25
  • 14mm X 1.50
  • 14mm X 2.00

IMPORTANT! A metric nut will start on an SAE thread and vice versa. But if you use an impact to install them, you might not notice that you stripped the lug threads until it’s too late. Then you’ll need new wheel lugs, too.

Don’t forget about left-hand threaded lug nuts. Many cars built up to the mid-1960s—we’re looking at you, Chrysler—used left- and right-hand threaded wheel lugs. Left-hand thread lug nuts are always marked with an L or LH to indicate such. If you try to remove a left-hand thread lug nut with an impact like it’s a regular right-hand thread one, you’ll be replacing a wheel lug.

man holding a short shank lug nut
This is a OEM cone-type lug nut with an external thread for a plastic lug covers or hubcap. You’ll find these a lot on GM vehicles from the 1990s through today. Many a plastic lug cap has been obliterated by an impact wrench, aka the ugga-dugga machine. (Image/Jefferson Bryant)

Other Considerations for Choosing the Best Lug Nuts

There is more to lug nuts than just style and size. Do you have a race car with extra-long studs? You need pass-thru lug nuts. Want to keep your expensive hoops safe from thieves? Locking lug nuts can help.

Many wheel makers minimize the space for the lug nuts, requiring the use of special ones like spline drive nuts. If you need specialty lug nuts, Summit Racing has every lug nut type you could ever need.

McGard Locking Lug Nuts
Theft sucks. You can slow down wheel thieves by using locking lug nuts like this from McGard. Just don’t lose the key! (Image/Summit Racing)

Proper Lug Nut Installation & Removal

Lug nuts and bolts should always be installed dry. That means absolutely no anti-seize, lubricant, oil, or penetrating oil. You want nothing but clean, dry metal. Always make sure you have the threads started correctly. One way to do this is to spin the nut backwards on the lug until it settles in place, then thread it on correctly. This aligns the threads so the nut goes on straight.

Thread depth is an often-ignored factor, but it is critical to a safe installation. The minimum thread engagement on a lug nut (or any nut for that matter) is the same as the width of the bolt. For example, a 12mm lug nut must thread onto the bolt a minimum of 12mm. If your lug nuts are blind (can’t see the wheel stud once installed), then you need to measure. Sometimes they can be eyeballed—but if it is questionable, get out the tape measure.

Don’t tighten a single lug nut until all of them are threaded to the wheel lugs. You want to tighten the lug nuts in three stages—hand-tight, wrench-tight, then torqued to spec with the weight of the vehicle on the wheels. This ensures that the wheel is centered and loaded for a proper torque value. Make sure that you use a crisscross pattern to tighten and torque the nuts for proper load distribution.

While many people (and shops) use an impact gun to tighten lug nuts, there are actual torque specs that should be followed. Nice and tight is good enough when on the side of the road, but when you’re the shop, take the extra five minutes to properly torque your lug nuts. The actual torque spec is listed in your vehicle’s owners manual, but here is a list of generic torque specs based on thread size:

General Fastener Torque Specs Based on Thread Size

Thread SizeGeneral Torque Spec
12mm70 – 80 ft.-lbs.
14mm85 – 90 ft.-lbs.
7/16 inch70 – 80 ft.-lbs.
1/2 inch75 – 85 ft.-lbs.
9/16 inch135 – 145 ft.-lbs.

It’s important to check and retorque the lug nuts after 50 to 100 miles of driving, especially if you have wheels made of aluminum or magnesium. One time we bolted on wheels and then 30 miles later, the lug nuts loosened because of the temperature change. Luckily, we were only doing 20 mph when it started wobbling, so disaster was averted.

Check your lug nuts after a heat cycle to make sure they are still tight!

The right lug nuts will give you peace of mind that your ride is safe and ready to roll. Don’t skimp on them—it will almost always bite you in the end.

Summit Racing Short Shank Lug Nuts
These are Summit Racing-brand short shank lug nuts . A washer is required. The shanks can vary wildly in depth, so make sure you get the ones your wheels require. The shank should not touch the wheel hub when installed. (Image/Summit Racing)
Summit Racing Spline Drive Lug Nuts
This is a Summit Racing Spline Lug Nut Installation Kit that includes the installation socket.
Spline drive lug nuts look cool, are theft-resistant, and don’t strip out as easily as standard hex lug nuts. (Image/Summit Racing)
Milwaukee Tool Lug Nut Impact Socket Set
It’s a good idea to have a quality set of dedicated lug nut sockets in your toolbox, especially if you own more than one vehicle. Milwaukee Tool offers several impact sockets and sets, available in both metric and SAE socket sizes. Each socket has a non-marring sleeve to protect the wheel. (Image/Summit Racing)
Lug Nut socket remover set
If you own European, Asian, or custom cars, a set of these multi-drive lug nut tools is crucial. It includes internal and external hex tools in different sizes. This kit has saved us a few times. (Image/Jefferson Bryant)
Milton Tool Lug Nut Extractor Socket Set
If you run into a stripped lug nut or lose the key to your locking lug nut, extractor sockets like these from Milton Tools work really well. (Image/Summit Racing)

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Jefferson Bryant has been a full-time automotive journalist since 2003. He has written countless how-to articles, nine books, and built several award-winning vehicles.