# 11/16" drill size

A 11/16 in drill is 0.6875 in (17.46 mm). It is the standard tap drill for 3/4-16 UNF; the nearest metric drill is 17.5 mm.

## 11/16" drill data

- Series: Fractional drill
- Decimal: 0.6875 in
- Metric: 17.46 mm (17.4625 mm exact)
- Nearest metric drill: 17.5 mm (+0.038 mm)
- Standard tap drill for: 3/4-16 UNF

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 17.4 mm | 0.6850 | −0.062 mm |
| 17.5 mm | 0.6890 | +0.038 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| #1 | Number | 0.2280 | 5.79 |
| Letter Z | Letter | 0.4130 | 10.49 |
| 43/64" | Fractional | 0.6719 | 17.07 |
| 11/16" | Fractional | 0.6875 | 17.46 |
| 45/64" | Fractional | 0.7031 | 17.86 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| 3/4-16 UNF | 11/16 | 77 |
| M20 × 2.5 | 17.5 mm | 78 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| 5/8" bolt | 0.6250" | 0.0625" | 0.0312" | – |
| M16 bolt | 16 mm | 1.46 mm | 0.73 mm | Close fit (close 17, normal 17.5 mm) |


## FAQ

**What size is a 11/16 in drill?**
A 11/16 in drill is 0.6875 in, which is 17.46 mm (17.4625 mm exactly).

**What is the metric equivalent of a 11/16 in drill?**
The nearest metric drill is 17.5 mm, 0.038 mm larger. The other close size is 17.4 mm.

**What tap uses a 11/16 in drill?**
A 11/16 in drill is the standard tap drill for 3/4-16 UNF (about 77 % thread).

**What does a 11/16 in drill clear?**
It clears a M16 bolt with 1.46 mm total clearance (0.73 mm per side); for metric bolts: close fit.

Source page: https://machinistcharts.com/drill-size/11-16-inch/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)