Menu

Shop

Garage

Cart

Account

Products to Compare (max of 3)
X
Compare These Parts

Wheel Lug Nut Size Guide + Torque Spec Chart

9/15/2015

This buyers guide explains how to select and install the proper lug nuts for your vehicle and/or aftermarket wheels in 5 easy steps.

  1. Seat Type
  2. Thread Size and Pitch
  3. Wrenching Type
  4. Appearance
  5. Torque Specifications
Seat Type

Determining the lug nut seat type that your wheels require is the first step in selecting the proper lug nuts for your needs. A 60 degree included angle tapered seat lug nut is a very common automotive lug nut design. The tapered seat will help center the wheel as the lug nuts are tightened and will typically yield a truer and more balanced assembly when compared to a shank or mag seat.

45 degree tapered seat lug nuts are exclusively used on circle track racing wheels. The 45 degree spec is a centerline angle measurement which makes it a 90 degree included angle. This lug nut taper is used for aftermarket racing wheel brands such as Speedway Motors, Aero, Bassett, etc. Never use 45 degree lug nuts on OEM wheels which have a 60 degree tapered seat. If your rules require 1” hex size circle track lug nuts and OEM wheels then you will need to machine the taper on your wheels to 45 degrees for a proper fit.

Shank or mag seat lug nuts have a flat seat and typically have a washer between the lug nut and the wheel. These lug nuts must be ordered by the shank diameter and shank length that is required for your wheels. Be sure not to order a shank diameter that is smaller than your wheels require since this will likely result in an out of balance and/or out of round assembly.

E/T Ultra tapered mag seat lug nuts incorporate a tapered seat with a shank on the end. These lug nuts are used on select wheels and wheel spacers/adapters.

Thread Size and Pitch

To determine the lug nut thread that is required for your vehicle the first step is to measure the thread size. Do this by measuring the outside diameter of the wheel stud threads on your vehicle. Using a tape measure on a threaded stud is difficult to get an accurate measurement so we suggest using a dial calipers or digital calipers to increase accuracy. Common thread diameters used for lug nuts in SAE sizes are 7/16, 1/2, 9/16 and 5/8”. Common metric thread diameters are 12 mm and 14 mm.

To determine the thread pitch on SAE threads you need to count the number of threads within a one inch long section of the stud. Use a tape measure to mark off a one inch section and count the number of threads. When counting be sure to only count the high points of the threads. Common thread pitch for SAE sizes are 11, 18, and 20 threads per inch making the most common SAE thread sizes 7/16”-20, 1/2"-20, 9/16”-18, 5/8”-18, and 5/8”-11.

To determine the thread pitch on Metric threads you need to find the number of threads within a one millimeter long section of the stud. Since this is extremely tough to estimate we suggest marking off a 10 millimeter long section, then after counting the threads divide your number by 10. Example: If you have 15 threads in a 10 mm section then that means there would be 1.5 threads per mm and the math looks like this: 15 ÷ 10 = 1.5

Common thread pitch for Metric threads are 1.25 and 1.50 threads per millimeter making the most common thread sizes 12 mm x 1.25, 12 mm x 1.50 and 14 mm x 1.50

Wrenching Type

Hex lug nuts are by far the most common. Easily available sockets or wrenches can be used to install or remove hex lug nuts which makes them the most popular. This allows the wheels to be removed or installed by any mechanic or tire shop when the vehicle needs service or repair. The downside is your wheels are more susceptible to being stolen when using hex lug nuts. If theft is a concern you may want to consider a set of wheel locks which are described in more detail next.

Spline drive lug nuts can be used to change the look or to match a wheel style. One spline drive lug nut per wheel can also be used for anti-theft purposes and are commonly called wheel locks. These lug nuts will require a very specific socket to install and remove them. Some kits come with the required socket and other kits the spline drive socket will be sold separately. A second socket for your spline drive lug nuts is a good idea in case one is damaged or lost. We recommend storing one in your toolbox at home and one in the glove box of your vehicle in case of a flat while traveling.

Hex key lug nuts provide a smooth outer appearance and are commonly used with wheels that have a very small counter bore for the lug nut to fit into. These lug nuts require a hex key to install or remove them. A benefit of this lug nut is you will not have any damage to the finish of the outer surface of the lug nuts when installing or removing them. The hex key is internal so any scuffs or scratches from the tools will be on the inside surface. With this style of lug nut you will need to carry special tools in your vehicle to remove them in case of a flat while on the road.

Appearance

Open end lug nuts are generally cheaper than other styles and used on vehicles which have hub caps that cover the lug nuts. Open lug nuts are also widely used for racing applications since some rules will require a specific amount of threads protruding past the end of the lug nut. If your rules do not specify a number of threads protruding past the lug nut then we suggest two threads minimum past the lug nut in racing applications for safety purposes.

Double sided lug nuts are primarily used in racing applications where pit stop times must be trimmed down to be as short as possible. The double sided design allows you to install the lug nut either direction so there is no fumbling around or lug nuts installed backwards.

Acorn lug nuts are used on all sorts of vehicles where the capped off appearance and no stud showing in the center is desirable. This provides a very clean appearance which makes them perfect for hot rods, muscle cars, show cars, and daily drivers.

The finish or color is also a consideration when buying lug nuts. Many open end lug nuts are zinc plated for corrosion resistance but they do not have the shine quality that would be desirable in some applications. A chrome plated finish provides a show quality shine that is suitable for many needs. There are also various black lug nut options to further customize the look to your particular wheels.

Lug Nut Torque Spec Chart

Now that you have chosen the proper lug nuts for your needs and are ready to install them the last step is to torque them properly. To accomplish this, we suggest using a 1/2” drive torque wrench. Torque the lug nuts in two steps, starting at 40 ft/lbs of torque for your first step to get the wheel seated properly. Then for the final torque refer to our chart below for torque recommendations based on your lug nut thread size. Be sure to follow the torque sequence shown above for your specific lug count.

Products Featured in this Article

Related Articles

Wheel Offset vs Backspacing Explained
by Joe McCollough - Posted in Tech
6/16/2021
This guide explains the difference between offset and backspacing when measuring wheels for your hot rod, muscle car or race car with helpful diagrams.
How To Measure Wheel Bolt Pattern
by Speedway Tech Team - Posted in Tech
9/19/2016
Learn how to measure wheel bolt circles with our wheel bolt pattern guide. Use this chart to make sure the rims you order match your wheel bolt pattern and fit your vehicle.
Determining the Best Performance Carburetor For Your Application
by Mark Houlahan - Posted in Tech
6/18/2021
We look at the basics of performance carburetion and what you need to properly supply your street or race car with enough fuel in this buyer's guide
Choosing the Right Headers
by Speedway Tech Team - Posted in Tech
6/16/2021
Which size of headers should I use? Short or long tube headers? Etc. Learn how to answer these exhaust questions and choose the right header with our expert guide.
Front Spring Choices for Traditional Straight Axle Hot Rods
by Mark Houlahan - Posted in Tech
6/15/2021
It may feel like a daunting task attempting to determine the best leaf spring for your traditional hot rod straight axle build, but our buyer's guide will surely help.
Solid Axle Choices for Your Traditional Hot Rod
by Eric McMillan - Posted in Tech
6/15/2021
When it comes to a traditional style build on an early hot rod it just has to be rolling on a solid front axle of some sort. In this buyer's guide we take you through I-beam and round tube solid axles, spindle choices, radius rod needs, and more.
How to Choose a Racing Suit
by Mark Houlahan - Posted in Tech
6/10/2021
Your body dimensions, field of racing, and budget are all factors in picking the best racing suit for your needs. Our racing suit buyer's guide will help educate you on all aspects of racing suit features and benefits so you can make an informed decision.
Old Tire Sizes Explained & Conversion Chart
by Speedway Tech Team - Posted in Tech
6/9/2021
Reference this old tire size conversion chart to equip your old car or truck with modern radial tires. Our tire fitment guide covers a variety of tire types and sizes.
How to Choose Racing Wheels
by Speedway Tech Team - Posted in Tech
6/8/2021
Check out this article to learn about why it's important to choose the right wheels for your race car and which types to choose.
Steering Shaft and U-Joint Selection Guide
by Speedway Tech Team - Posted in Tech
6/3/2021
Designing a steering system for your street rod or muscle car can be tricky. In this buyer's guide we'll show you how to choose the right steering U-joints, steering shaft, and accessories to complete the job quickly and safely.
Error
X
Note
X
Ok