#12-24 UNC thread: 5.49 mm × 24 TPI
Threads › #12-24 UNC
#12-24 UNC is a UNC thread: 5.49 mm major diameter, 24 TPI (1.058 mm pitch), 60° form.
| Standard | UNC |
|---|---|
| Major diameter | 5.486 mm (0.216″) |
| Pitch | 24 TPI (1.058 mm) |
| Thread angle | 60° |
| Minor diameter, bolt | 4.19 mm |
| Minor diameter, nut | 4.34 mm |
| Tap drill | Not listed. Check your tap maker's chart. |
| Usual class | 2A bolt, 2B nut |
Minor diameters worked out from the basic profile: major Ø − 1.22687 × pitch (bolt) and − 1.08253 × pitch (nut).
Open #12-24 UNC in BenchsmithAdd to order list
Measure it
Bolt: Measure across the crests of the bolt with the caliper jaws. Worn bolts read 0.1 to 0.3 under.
Nut or tapped hole: Measure across the tops of the threads inside the nut or hole with the inside jaws. That is the minor Ø. Worn or oversize holes read a little over.
Close in size, won't mate
- M5Ø5 mm, 0.8 mm pitch
- M6Ø6 mm, 1 mm pitch
- M6×0.75Ø6 mm, 0.75 mm pitch
- #10-32 UNFØ4.83 mm, 32 TPI
- 3/16 BSWØ4.76 mm, 24 TPI
- 1/4-28 UNFØ6.35 mm, 28 TPI
One size up or down
- #10-24 UNCØ4.83 mm (down)
- 1/4-20 UNCØ6.35 mm (up)
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.