M5 × 0.8 Tap Drill Size & Thread Specs
Everything for a M5 × 0.8 coarse pitch thread on one page: tap drill (4.2 mm), clearance holes, wrench and hex key sizes, and the nearest inch thread.
SP-TD-01 · M5 × 0.8
M5 × 0.8 specs
SizePlate
M5 × 0.8 · tap with
4.2 mm drill
.1654″
4.2 mm · 77% thread
- Inch drill
- #19 · .1660
- Clearance
- 5.3 / 5.5 mm
- Wrench
- 8 mm
- Cap screw key
- 4 mm
Thread
- Nominal size
- M5 · .1969″
- Pitch
- 0.8 mm · 31.7 TPI
- Series
- coarse
- fine pitch
- M5 × 0.5
Drilling
- Tap drill
- 4.2 mm · .1654
- Inch substitute
- #19 · .1660
- Close fit
- 5.3 mm
- Normal fit
- 5.5 mm
- Free fit
- 5.8 mm
Tools
- Hex head (ISO 4017)
- 8 mm
- Hex head (DIN 933)
- 8 mm
- Socket head cap key
- 4 mm
- Button head key
- 3 mm
- Flat head key
- 3 mm
Nearest inch
- Thread
- #10-24
- Major diameter
- .1900″
- Threads per inch
- 24
- Tap drill
- #25
- 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 |
|---|---|---|---|
| 4.2 mm | .1654 | 4.2 | 77% |
| #19 | .1660 | 4.22 | 75% |
| 4.3 mm | .1693 | 4.3 | 67% |
| #18 | .1695 | 4.31 | 67% |
| 11/64 | .1719 | 4.37 | 61% |
| #17 | .1730 | 4.39 | 58% |
| 4.4 mm | .1732 | 4.4 | 58% |
| #16 | .1770 | 4.5 | 49% |
| 4.5 mm | .1772 | 4.5 | 48% |
Neighboring sizes
- M3 × 0.35tap 2.65 mm
- M4 × 0.7tap 3.3 mm
- M4 × 0.5tap 3.5 mm
- M5 × 0.5tap 4.5 mm
- M6 × 1.0tap 5 mm
- M6 × 0.75tap 5.2 mm
Questions
What does M5 × 0.8 mean?
An ISO metric thread with a 5 mm major diameter and a 0.8 mm pitch (the distance from one thread crest to the next). It’s the coarse pitch for M5.
Can I use a #19 drill instead?
Usually. #19 is .1660″ against .1654″ for the 4.2 mm drill, which changes the thread engagement by a few percent at most.