# 57/64" drill size

A 57/64 in drill is 0.8906 in (22.62 mm). It sits between 7/8 in and 29/32 in in the fractional series; the nearest metric drill is 22.6 mm.

## 57/64" drill data

- Series: Fractional drill
- Decimal: 0.8906 in
- Metric: 22.62 mm (22.6219 mm exact)
- Nearest metric drill: 22.6 mm (−0.022 mm)

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 22.6 mm | 0.8898 | −0.022 mm |
| 22.7 mm | 0.8937 | +0.078 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| #1 | Number | 0.2280 | 5.79 |
| Letter Z | Letter | 0.4130 | 10.49 |
| 7/8" | Fractional | 0.8750 | 22.22 |
| 57/64" | Fractional | 0.8906 | 22.62 |
| 29/32" | Fractional | 0.9062 | 23.02 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| 1-8 UNC | 7/8 | 67 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| M20 bolt | 20 mm | 2.62 mm | 1.31 mm | Normal fit (normal 22, loose 24 mm) |
| M22 bolt | 22 mm | 0.62 mm | 0.31 mm | Tighter than close fit (23 mm) |
| 7/8" bolt | 0.8750" | 0.0156" | 0.0078" | – |


## FAQ

**What size is a 57/64 in drill?**
A 57/64 in drill is 0.8906 in, which is 22.62 mm (22.6219 mm exactly).

**What is the metric equivalent of a 57/64 in drill?**
The nearest metric drill is 22.6 mm, 0.022 mm smaller. The other close size is 22.7 mm.

**What thread can I tap with a 57/64 in drill?**
It leaves about 67 % thread in 1-8 UNC.

**What does a 57/64 in drill clear?**
It clears a 7/8" bolt with 0.0156" total clearance (0.0078" per side).

Source page: https://machinistcharts.com/drill-size/57-64-inch/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)