#0-80 Tap Drill Size & Thread Specs
Everything for a #0-80 UNF thread on one page: tap drill (3/64), clearance holes, wrench and hex key sizes, and the nearest metric thread.
SP-TD-01 · #0-80
#0-80 specs
SizePlate
#0-80 UNF · tap with
3/64 drill
.0469″
1.19 mm · 81% thread
- Metric drill
- 1.2 mm · .0472
- Clearance
- #52 / #50
Thread
- Nominal size
- #0 · 1.52 mm
- Major diameter
- .0600″
- Threads per inch
- 80
- Pitch
- .0125″ · 0.318 mm
- Series
- UNF (fine)
Drilling
- Tap drill (75%)
- 3/64 · .0469
- Metric substitute
- 1.2 mm · .0472
- Tap drill (≈50%)
- #55 · .0520
- Close fit
- #52 · .0635
- Free fit
- #50 · .0700
Nearest metric
- Thread
- M1.6 × 0.35
- Major diameter
- 1.6 mm
- Pitch
- 0.35 mm
- Tap drill
- 1.25 mm
- Interchangeable
- No
Not interchangeable means the threads look close but won't run together: forcing one into the other strips both.
Drill size by thread percentage
Larger drill, less thread, easier tapping. 75% is the usual target.
| Drill | Decimal | mm | Thread |
|---|---|---|---|
| #56 | .0465 | 1.18 | 83% |
| 3/64 | .0469 | 1.19 | 81% |
| 1.2 mm | .0472 | 1.2 | 79% |
| 1.25 mm | .0492 | 1.25 | 66% |
| 1.3 mm | .0512 | 1.3 | 54% |
| #55 | .0520 | 1.32 | 49% |
Neighboring sizes
Questions
What does #0-80 mean?
A #0 nominal diameter with 80 threads per inch. It’s the fine (UNF) thread for that size.
Can I use a 1.2 mm drill instead of 3/64?
Usually. 1.2 mm is .0472″ against .0469″ for 3/64, which changes the thread engagement by a few percent at most. The thread-percentage table above shows exactly how much thread each nearby drill leaves.