# 37/64" drill size

A 37/64 in drill is 0.5781 in (14.68 mm). It is the standard tap drill for 5/8-18 UNF; the nearest metric drill is 14.7 mm.

## 37/64" drill data

- Series: Fractional drill
- Decimal: 0.5781 in
- Metric: 14.68 mm (14.6844 mm exact)
- Nearest metric drill: 14.7 mm (+0.016 mm)
- Standard tap drill for: 5/8-18 UNF

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 14.6 mm | 0.5748 | −0.084 mm |
| 14.7 mm | 0.5787 | +0.016 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| #1 | Number | 0.2280 | 5.79 |
| Letter Z | Letter | 0.4130 | 10.49 |
| 9/16" | Fractional | 0.5625 | 14.29 |
| 37/64" | Fractional | 0.5781 | 14.68 |
| 19/32" | Fractional | 0.5938 | 15.08 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| 5/8-18 UNF | 37/64 | 65 |
| M16 × 1.5 | 14.5 mm | 68 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| M14 bolt | 14 mm | 0.68 mm | 0.34 mm | Tighter than close fit (15 mm) |
| 9/16" bolt | 0.5625" | 0.0156" | 0.0078" | – |


## FAQ

**What size is a 37/64 in drill?**
A 37/64 in drill is 0.5781 in, which is 14.68 mm (14.6844 mm exactly).

**What is the metric equivalent of a 37/64 in drill?**
The nearest metric drill is 14.7 mm, 0.016 mm larger. The other close size is 14.6 mm.

**What tap uses a 37/64 in drill?**
A 37/64 in drill is the standard tap drill for 5/8-18 UNF (about 65 % thread).

**What does a 37/64 in drill clear?**
It clears a 9/16" bolt with 0.0156" total clearance (0.0078" per side).

Source page: https://machinistcharts.com/drill-size/37-64-inch/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)