How to measure Wheel Studs

A broken wheel stud needs to be replaced immediately for safety. A wheel stud that has had its threads stripped needs to be replaced quickly before more damage can occur to the stud or wheel and tyre assembly while in use. Factory and performance wheel studs can be purchased easily if you know exactly what you need to know to order the right ones. Now you can buy replacement wheel studs with confidence after reading these easy to follow steps.

Step 1:
Remove the wheel stud that needs to be replaced using a hammer to hit it out or a spanner to thread it out of its splined or threaded wheel stud port. Your wheel stud will either be screwed in or pushed into position. For the threaded ports you will use the correct spanner to loosen it from its mounting hole. For pushed-in wheel studs you will be able to hammer the stud out from the front. Spray the wheel stud liberally with WD-40 prior to attempting to remove the old wheel stud. These studs are prone to corrosion and can become locked into position. Use the correct tools and steady pressure to remove the old wheel stud(s). Because getting old wheel studs out can be difficult, this is the recommended procedure to easily remove old wheel studs that need to be replaced.

Step 2:
Measure the old wheel stud if it is not broken. You may need to measure a good wheel stud to get the correct sized replacement wheel stud if the one you are replacing is broken. Measuring a wheel stud with a vernier caliper will give you the best measurements for buying a new replacement wheel stud. You will need to measure the overall length of the stud, the diameter of the threaded shaft and the diameter of the knurl or collar of the bolt directly under the stud head. Besides the physical dimensions of the old wheel stud, you will need to know the thread type. A threaded knurl will either turn to the right or left when loosened. Make note of the direction when removing so that you buy the correct replacement wheel stud.

You can use a thread pitch gauge to determine the number of threads per inch or the distance between threads in metric connections. Place the gauge on the threads until the fit is snug. Another way of checking the thread type, is to buy a new nut that specifies the thread type on the box and if it screws successfully onto the thread, then that's the thread you need to order.

Measuring Wheel Studs

 

Above is picture of a typical wheel stud. You can use this diagram to correctly identify each part of the wheel stud that needs measuring.

For example:

A - Thread Diameter
B - Stud Length
C - Knurl Length
D - Base Length
E - Knurl Diameter
F - Thread Length

 

You can use a normal tape measure to do this, however a vernier caliper is more accurate. 

  • Make sure that whatever you are measuring is clean and has no burrs on the edges.
  • Open the jaws of the caliper and position them on both sides of the piece you are measuring.
  • Push the jaws firmly against the work piece.
  • Lock the clamp screw so that the jaws don't move.
  • On the vernier scale is a small number 0. Look at how many inch divisions it is past on the bar scale.