M12×1 thread
M12×1 tap drill
11 mm
Clearance hole 13 mm · 18 mm hex
M12×1 is a fine metric thread with a 12 mm (0.472") major diameter and 1 mm pitch. Tap it with a 11 mm drill; drill 13 mm to pass a bolt through.
The numbers
- Designation
- M12×1
- Major diameter
- 12 mm / 0.472"
- Minor diameter
- 10.917 mm
- Pitch
- 1 mm pitch
- Tap drill (75% thread)
- 11 mm — 11 mm
- Clearance hole (close fit)
- 13 mm / 0.512"
- Hex across flats
- 18 mm
How to measure what you have
- Measure across the thread crests with calipers. A used M12×1 reads a little under 12 mm — the crests are truncated by the standard, then worn and plated, so anything from about 11.6 mm up is consistent with this size.
- Measure the pitch: put a rule against the threads and count the distance over ten crests, then divide by ten. This one should give 1 mm.
- A thread pitch gauge settles it in seconds and costs very little. Guessing between a coarse and a fine thread of the same diameter is the usual way a thread gets stripped.
Tightening torque
Typical torque
82–110 N·m
60.5–81.1 lb·ft
Plain steel property class 8.8 or SAE grade 5, dry threads, tightened to about 65% of yield. Lubricated threads reach the same preload at 20-30% less torque. Where the manufacturer publishes a figure — spark plugs, wheel nuts, cylinder heads — use theirs.
Where this size turns up
- Instrument and sensor bodies
- Fine adjusters and lock nuts
Other threads at this diameter
| Thread | Pitch | Tap drill | Clearance |
|---|---|---|---|
| M12×1.75 | 1.75 mm | 10.2 mm | 13 mm |
| M12×1.5 | 1.5 mm | 10.5 mm | 13 mm |
| M12×1.25 | 1.25 mm | 10.8 mm | 13 mm |
Common questions
- What size drill for an M12×1 tap?
- 11 mm (11 mm), which gives about 75% thread engagement.
- What clearance hole for M12×1?
- 13 mm for a close fit — enough to pass the bolt without slop.
- What spanner fits M12×1?
- 18 mm across the flats on a standard hex head.
Related pages
- M12×1.75 10.2 mm tap drill
- M12×1.5 10.5 mm tap drill
- M12×1.25 10.8 mm tap drill
- M10×1.5 8.5 mm tap drill
- M14×2 12 mm tap drill
- M10×1.25 8.8 mm tap drill
- M10×1 9 mm tap drill
- M14×1.5 12.5 mm tap drill
- M14×1.25 12.8 mm tap drill
- M8×1.25 6.8 mm tap drill
- M16×2 14 mm tap drill
- M8×1 7 mm tap drill
- M8×0.75 7.2 mm tap drill
Sources
- Official vendor product documentation — At One Place
- Typical range compiled from manufacturer specifications — At One Place