2-4.5 UNC thread: 50.8 mm × 4.5 TPI
Threads › 2-4.5 UNC
2-4.5 UNC is a UNC thread: 50.8 mm major diameter, 4.5 TPI (5.644 mm pitch), 60° form.
| Standard | UNC |
|---|---|
| Major diameter | 50.8 mm (2″) |
| Pitch | 4.5 TPI (5.644 mm) |
| Thread angle | 60° |
| Minor diameter, bolt | 43.88 mm |
| Minor diameter, nut | 44.69 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 2-4.5 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
One size up or down
- 1-3/4-5 UNCØ44.45 mm (down)
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.