Help · Finder
Tire Stud Size Finder
Match the TSMI stud size to the tire's stud holes, then see the studs and stud guns we stock for it.
What Size Stud?
If the sidewall lists a TSMI number, use it. If not, measure a stud hole with a tread depth gauge and tap the reading.
Hole depth (in 32nds of an inch) or TSMI number
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Measure the Stud Hole
- Check the sidewall. Many studdable winter tires list the TSMI stud size there or on a sticker.
- Measure if it isn't marked. Push a tread depth gauge into a stud hole. The reading in 32nds is the TSMI number: 13/32 in takes a TSMI #13.
- Use only that size. A stud that is too long can puncture the tire. One that is too short may never touch the road.
- Stud new tires only. Tires that have been driven on can have debris packed in the holes, so they shouldn't be studded or re-studded.
- Wet each hole with water before you set the stud. It eases the install and is easier on the gun.
- Check the seat. A correct stud leaves only the carbide pin above the tread, with the flange at the bottom of the hole.
Before you stud: stud laws and seasons vary by state, so check local rules. A passenger tire takes about 80 to 120 studs, depending on its size and hole pattern.
TSMI Sizes
| TSMI | Hole depth | Metric | Overall length | Base flange | Used in |
|---|---|---|---|---|---|
| #11 | 11/32 in | 8.8-10/1 | 10 mm | 8.8 mm | Passenger, light truck |
| #12 | 12/32 in | 8.8-11/1 | 11 mm | 8.8 mm | Passenger, light truck |
| #13 | 13/32 in | 8.8-12/1 | 12 mm | 8.8 mm | Passenger, light truck |
| #15 | 15/32 in | 8.8-13/1 | 13 mm | 8.8 mm | Passenger, light truck |
| #16 | 16/32 in | 8.8-15/1 | 15 mm | 8.8 mm | Passenger, light truck |
| #17 | 17/32 in | 8.8-16/1 | 16 mm | 8.8 mm | Passenger, light truck |
| #19 | 19/32 in | 10.8-17/1 | 17 mm | 10.8 mm | Truck, plow, loader; ice resurfacer tires |
| #21 | 21/32 in | 10.8-19/1 | 19 mm | 10.8 mm | Truck, plow, loader |
The TSMI number is the hole depth in 32nds, not the stud length. Metric designation is base flange in mm, then overall length.
Setting up a studding station?
Guns, feeders, drill bits and repair kits are in Stud Tools. Questions? Call 800-328-7400.
- Sources: McGee Company, Stud Basics (TSMI number and hole depth, wetting the hole); Discount Tire studding guide and store talk (measuring, wrong size risks); Tire Rack, Tire Studs (new tires only, correct insertion, sizes #11 to #17); Rubber Inc (sidewall size, 80 to 120 studs per tire); our Bruno Wessel listings (#19, #21).