# #80 drill size

A #80 drill is 0.0135 in (0.34 mm). It is the smallest number drill on this chart; the nearest metric drill is 0.35 mm.

## #80 drill data

- Series: Number drill
- Decimal: 0.0135 in
- Metric: 0.34 mm (0.3429 mm exact)
- Nearest metric drill: 0.35 mm (+0.007 mm)
- Nearest fractional: 1/64" (0.0156 in)

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 0.3 mm | 0.0118 | −0.043 mm |
| 0.35 mm | 0.0138 | +0.007 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| #80 | Number | 0.0135 | 0.34 |
| #79 | Number | 0.0145 | 0.37 |
| 1/64" | Fractional | 0.0156 | 0.40 |
| Letter A | Letter | 0.2340 | 5.94 |


## FAQ

**What size is a #80 drill?**
A #80 drill is 0.0135 in, which is 0.34 mm (0.3429 mm exactly).

**What is the metric equivalent of a #80 drill?**
The nearest metric drill is 0.35 mm, 0.007 mm larger. The other close size is 0.3 mm.

**Which fractional drill is closest to #80?**
1/64 in (0.0156 in) is the closest, 0.0021 in larger.

Source page: https://machinistcharts.com/drill-size/number-80/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)