# #52 drill size

A #52 drill is 0.0635 in (1.61 mm). It sits between #53 and #51 in the number series; the nearest metric drill is 1.6 mm.

## #52 drill data

- Series: Number drill
- Decimal: 0.0635 in
- Metric: 1.61 mm (1.6129 mm exact)
- Nearest metric drill: 1.6 mm (−0.013 mm)
- Nearest fractional: 1/16" (0.0625 in)

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 1.6 mm | 0.0630 | −0.013 mm |
| 1.65 mm | 0.0650 | +0.037 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| #53 | Number | 0.0595 | 1.51 |
| 1/16" | Fractional | 0.0625 | 1.59 |
| #52 | Number | 0.0635 | 1.61 |
| #51 | Number | 0.0670 | 1.70 |
| 5/64" | Fractional | 0.0781 | 1.98 |
| Letter A | Letter | 0.2340 | 5.94 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| M2 × 0.4 | 1.6 mm | 74 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| M1.6 bolt | 1.6 mm | 0.01 mm | 0.01 mm | Tighter than close fit (1.7 mm) |


## FAQ

**What size is a #52 drill?**
A #52 drill is 0.0635 in, which is 1.61 mm (1.6129 mm exactly).

**What is the metric equivalent of a #52 drill?**
The nearest metric drill is 1.6 mm, 0.013 mm smaller. The other close size is 1.65 mm.

**What thread can I tap with a #52 drill?**
It leaves about 74 % thread in M2 × 0.4.

**Which fractional drill is closest to #52?**
1/16 in (0.0625 in) is the closest, 0.0010 in smaller.

**What does a #52 drill clear?**
It clears a M1.6 bolt with 0.01 mm total clearance (0.01 mm per side); for metric bolts: tighter than close fit.

Source page: https://machinistcharts.com/drill-size/number-52/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)