# 13/64" drill size

A 13/64 in drill is 0.2031 in (5.16 mm). It sits between 3/16 in and 7/32 in in the fractional series; the nearest metric drill is 5.2 mm.

## 13/64" drill data

- Series: Fractional drill
- Decimal: 0.2031 in
- Metric: 5.16 mm (5.1594 mm exact)
- Nearest metric drill: 5.2 mm (+0.041 mm)
- Nearest number drill: #6 (0.2040 in)

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 5.1 mm | 0.2008 | −0.059 mm |
| 5.2 mm | 0.2047 | +0.041 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| 3/16" | Fractional | 0.1875 | 4.76 |
| #7 | Number | 0.2010 | 5.11 |
| 13/64" | Fractional | 0.2031 | 5.16 |
| #6 | Number | 0.2040 | 5.18 |
| 7/32" | Fractional | 0.2188 | 5.56 |
| Letter A | Letter | 0.2340 | 5.94 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| 1/4-20 UNC | #7 | 72 |
| M6 × 1 | 5 mm | 65 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| #8 screw | 0.1640" | 0.0391" | 0.0196" | – |
| #10 screw | 0.1900" | 0.0131" | 0.0066" | – |
| M5 bolt | 5 mm | 0.16 mm | 0.08 mm | Tighter than close fit (5.3 mm) |


## FAQ

**What size is a 13/64 in drill?**
A 13/64 in drill is 0.2031 in, which is 5.16 mm (5.1594 mm exactly).

**What is the metric equivalent of a 13/64 in drill?**
The nearest metric drill is 5.2 mm, 0.041 mm larger. The other close size is 5.1 mm.

**What thread can I tap with a 13/64 in drill?**
It leaves about 72 % thread in 1/4-20 UNC and 65 % in M6 × 1.

**Which number or letter drill is closest to 13/64 in?**
#6 (0.2040 in) is the closest, 0.0009 in larger.

**What does a 13/64 in drill clear?**
It clears a M5 bolt with 0.16 mm total clearance (0.08 mm per side); for metric bolts: tighter than close fit.

Source page: https://machinistcharts.com/drill-size/13-64-inch/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)