# #53 drill size

A #53 drill is 0.0595 in (1.51 mm). It is the standard tap drill for #1-64 UNC and #1-72 UNF; the nearest metric drill is 1.5 mm.

## #53 drill data

- Series: Number drill
- Decimal: 0.0595 in
- Metric: 1.51 mm (1.5113 mm exact)
- Nearest metric drill: 1.5 mm (−0.011 mm)
- Nearest fractional: 1/16" (0.0625 in)
- Standard tap drill for: #1-64 UNC, #1-72 UNF

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 1.5 mm | 0.0591 | −0.011 mm |
| 1.55 mm | 0.0610 | +0.039 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| 3/64" | Fractional | 0.0469 | 1.19 |
| #54 | Number | 0.0550 | 1.40 |
| #53 | Number | 0.0595 | 1.51 |
| 1/16" | Fractional | 0.0625 | 1.59 |
| #52 | Number | 0.0635 | 1.61 |
| Letter A | Letter | 0.2340 | 5.94 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| #1-72 UNF | #53 | 75 |
| #1-64 UNC | #53 | 67 |


## FAQ

**What size is a #53 drill?**
A #53 drill is 0.0595 in, which is 1.51 mm (1.5113 mm exactly).

**What is the metric equivalent of a #53 drill?**
The nearest metric drill is 1.5 mm, 0.011 mm smaller. The other close size is 1.55 mm.

**What tap uses a #53 drill?**
A #53 drill is the standard tap drill for #1-64 UNC (about 67 % thread) and #1-72 UNF (about 75 % thread).

**Which fractional drill is closest to #53?**
1/16 in (0.0625 in) is the closest, 0.0030 in larger.

Source page: https://machinistcharts.com/drill-size/number-53/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)