---
title: "M10×1.5 tap drill 8.5 mm, clearance 10.5 mm"
description: "M10×1.5: tap drill 8.5 mm, clearance hole 10.5 mm, 16 mm hex. Full thread dimensions, how to identify it, and torque."
url: https://atoneplace.net/fastener/m10-1-5/
site: "At One Place"
---

# M10×1.5 thread

**M10×1.5 tap drill: 8.5 mm**

Clearance hole 10.5 mm · 16 mm hex

M10×1.5 is a coarse metric thread with a 10 mm (0.394") major diameter and 1.5 mm pitch. Tap it with a 8.5 mm drill; drill 10.5 mm to pass a bolt through.

## The numbers

- **Designation:** M10×1.5
- **Major diameter:** 10 mm / 0.394"
- **Minor diameter:** 8.376 mm
- **Pitch:** 1.5 mm pitch
- **Tap drill (75% thread):** 8.5 mm — 8.5 mm
- **Clearance hole (close fit):** 10.5 mm / 0.413"
- **Hex across flats:** 16 mm

## How to measure what you have

1. Measure across the thread crests with calipers. A used M10×1.5 reads a little under 10 mm — the crests are truncated by the standard, then worn and plated, so anything from about 9.6 mm up is consistent with this size.
2. Measure the pitch: put a rule against the threads and count the distance over ten crests, then divide by ten. This one should give 1.5 mm.
3. 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: 41–56 N·m**

30.2–41.3 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

- Brake caliper and suspension bolts on cars
- Motorcycle axle pinch bolts
- Engine and gearbox mounting bolts
- Scaffolding and staging fittings

> ISO 4014 and ISO 4032 give 16 mm across flats; the older DIN 931 and DIN 934 parts you will still find in a drawer take a 17 mm spanner.

## Other threads at this diameter

*Same diameter, different pitch. Forcing the wrong one strips the thread in a turn or two.*

| Thread | Pitch | Tap drill | Clearance |
| --- | --- | --- | --- |
| M10×1.25 | 1.25 mm | 8.8 mm | 10.5 mm |
| M10×1 | 1 mm | 9 mm | 10.5 mm |

## Common questions

### What size drill for an M10×1.5 tap?

8.5 mm (8.5 mm), which gives about 75% thread engagement.

### What clearance hole for M10×1.5?

10.5 mm for a close fit — enough to pass the bolt without slop.

### What spanner fits M10×1.5?

16 mm across the flats on a standard hex head.

## Related pages

- [M10×1.25](https://atoneplace.net/fastener/m10-1-25/)
- [M10×1](https://atoneplace.net/fastener/m10-1/)
- [M8×1.25](https://atoneplace.net/fastener/m8-1-25/)
- [M12×1.75](https://atoneplace.net/fastener/m12-1-75/)
- [M8×1](https://atoneplace.net/fastener/m8-1/)
- [M8×0.75](https://atoneplace.net/fastener/m8-0-75/)
- [M12×1.5](https://atoneplace.net/fastener/m12-1-5/)
- [M12×1.25](https://atoneplace.net/fastener/m12-1-25/)
- [M12×1](https://atoneplace.net/fastener/m12-1/)
- [M6×1](https://atoneplace.net/fastener/m6-1/)
- [M14×2](https://atoneplace.net/fastener/m14-2/)
- [M6×0.75](https://atoneplace.net/fastener/m6-0-75/)

## Sources

- Official vendor product documentation — At One Place (/about/)
- Typical range compiled from manufacturer specifications — At One Place (/about/)