BSPT Tapered Pipe Thread (R / Rp / Rc) · ISO 7-1 / EN 10226
R 3/8" Thread: Pitch, Tap Drill & Dimensions
R 3/8" is a BSPT Tapered Pipe Thread (R / Rp / Rc) (ISO 7-1 / EN 10226) size, with a major diameter of 16.662 mm, 19 threads per inch (1.337 mm pitch). The tap drill is 14.950 mm.
| Female Thread Diameter | Rp 3/8" |
|---|---|
| Pipe Minor Diameter (mm) | 10 |
| Pipe Major Diameter (mm) | 16.662 |
| Tapping Drill Size (mm) | 14.950 |
| TPI | 19 |
| Pitch (mm) | 1.337 |
| Flank angle | 55° |
| Taper | 1:16 |
Common questions
What size drill do I use to tap R 3/8"?
Use a 14.950 drill. This is the standard tap drill for R 3/8"; for hard materials or deep threads a slightly larger drill reduces tapping torque.
What is the pitch of R 3/8"?
The pitch of R 3/8" is 1.337, meaning the thread advances that distance in one full turn.
Where can I find other BSPT Tapered Pipe Thread (R / Rp / Rc) sizes?
The full BSPT Tapered Pipe Thread (R / Rp / Rc) table, with every size and a live filter, is on its standard page, and the Thread Finder searches all 73 standards at once.
Reference values; computed values use the ISO basic profile. Verify against the current standard before production use.