5/16-24 UNF thread: 7.94 mm × 24 TPI
Threads › 5/16-24 UNF
5/16-24 UNF is a UNF thread: 7.94 mm major diameter, 24 TPI (1.058 mm pitch), 60° form. Tap drill 6.9 mm.
| Standard | UNF |
|---|---|
| Major diameter | 7.938 mm (0.313″) |
| Pitch | 24 TPI (1.058 mm) |
| Thread angle | 60° |
| Minor diameter, bolt | 6.64 mm |
| Minor diameter, nut | 6.79 mm |
| Tap drill | 6.9 mm |
| 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 5/16-24 UNF 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.
Same diameter, other pitch
- 5/16-18 UNC18 TPI (1.411 mm pitch)
- 5/16 BSW18 TPI (1.411 mm pitch)
Close in size, won't mate
- 5/16-14 ACMEØ7.94 mm, 14 TPI
- M8Ø8 mm, 1.25 mm pitch
- M8×1Ø8 mm, 1 mm pitch
- Tr8×1.5Ø8 mm, 1.5 mm pitch
- G1/16Ø7.72 mm, 28 TPI
One size up or down
- 1/4-28 UNFØ6.35 mm (down)
- 3/8-24 UNFØ9.52 mm (up)
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.