1-1/2 BSW thread: 38.1 mm × 6 TPI
Threads › 1-1/2 BSW
1-1/2 BSW is a BSW Whitworth thread: 38.1 mm major diameter, 6 TPI (4.233 mm pitch), 55° form.
| Standard | BSW Whitworth |
|---|---|
| Major diameter | 38.1 mm (1.5″) |
| Pitch | 6 TPI (4.233 mm) |
| Thread angle | 55° |
| Minor diameter, bolt | 32.68 mm |
| Minor diameter, nut | 32.68 mm |
| Tap drill | Not listed. Check your tap maker's chart. |
Minor diameters worked out from the basic profile: major Ø − 1.28065 × pitch.
Open 1-1/2 BSW 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
- 1-1/2-6 UNC6 TPI (4.233 mm pitch)
- 1-1/2-12 UNF12 TPI (2.117 mm pitch)
Close in size, won't mate
- 1-1/2-4 ACMEØ38.1 mm, 4 TPI
- M39Ø39 mm, 4 mm pitch
- M39×3Ø39 mm, 3 mm pitch
One size up or down
- 1-1/4 BSWØ31.75 mm (down)
Got a bolt and no idea what it is? Measure the outside Ø and type it into Benchsmith → Find → Thread.