M1.6 × 0.35 Tap Drill Size & Thread Specs
Everything for a M1.6 × 0.35 coarse pitch thread on one page: tap drill (1.25 mm), clearance holes, wrench and hex key sizes, and the nearest inch thread.
SP-TD-01 · M1.6 × 0.35
M1.6 × 0.35 specs
SizePlate
M1.6 × 0.35 · tap with
1.25 mm drill
.0492″
1.25 mm · 77% thread
- Inch drill
- 3/64 · .0469
- Clearance
- 1.7 / 1.8 mm
Thread
- Nominal size
- M1.6 · .0630″
- Pitch
- 0.35 mm · 72.6 TPI
- Series
- coarse
Drilling
- Tap drill
- 1.25 mm · .0492
- Inch substitute
- 3/64 · .0469
- Close fit
- 1.7 mm
- Normal fit
- 1.8 mm
- Free fit
- 2 mm
Nearest inch
- Thread
- #1-64
- Major diameter
- .0730″
- Threads per inch
- 64
- Tap drill
- #53
- 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 |
|---|---|---|---|
| 1.25 mm | .0492 | 1.25 | 77% |
| 1.3 mm | .0512 | 1.3 | 66% |
| #55 | .0520 | 1.32 | 61% |
| #54 | .0550 | 1.4 | 45% |
Neighboring sizes
- M2 × 0.4tap 1.6 mm
- M2.5 × 0.45tap 2.05 mm
- M3 × 0.5tap 2.5 mm
- M3 × 0.35tap 2.65 mm
- M4 × 0.7tap 3.3 mm
- M4 × 0.5tap 3.5 mm
Questions
What does M1.6 × 0.35 mean?
An ISO metric thread with a 1.6 mm major diameter and a 0.35 mm pitch (the distance from one thread crest to the next). It’s the coarse pitch for M1.6.
Can I use a 3/64 drill instead?
Usually. 3/64 is .0469″ against .0492″ for the 1.25 mm drill, which changes the thread engagement by a few percent at most.