# #29 drill size

A #29 drill is 0.1360 in (3.45 mm). It is the standard tap drill for #8-32 UNC and #8-36 UNF; the nearest metric drill is 3.5 mm.

## #29 drill data

- Series: Number drill
- Decimal: 0.1360 in
- Metric: 3.45 mm (3.4544 mm exact)
- Nearest metric drill: 3.5 mm (+0.046 mm)
- Nearest fractional: 9/64" (0.1406 in)
- Standard tap drill for: #8-32 UNC, #8-36 UNF

## Nearest metric drills

| Metric drill | Inch | Difference |
|---|---|---|
| 3.4 mm | 0.1339 | −0.054 mm |
| 3.5 mm | 0.1378 | +0.046 mm |

## Nearby inch drills

| Drill | Series | Inch | mm |
|---|---|---|---|
| 1/8" | Fractional | 0.1250 | 3.17 |
| #30 | Number | 0.1285 | 3.26 |
| #29 | Number | 0.1360 | 3.45 |
| #28 | Number | 0.1405 | 3.57 |
| 9/64" | Fractional | 0.1406 | 3.57 |
| Letter A | Letter | 0.2340 | 5.94 |

## Threads this drill can tap

| Thread | Standard drill | Thread % with this drill |
|---|---|---|
| #8-36 UNF | #29 | 78 |
| #8-32 UNC | #29 | 69 |
| M4 × 0.5 | 3.5 mm | 84 |
| M4 × 0.7 | 3.3 mm | 60 |

## Clearance

| Fastener | Diameter | Clearance | Per side | ISO 273 |
|---|---|---|---|---|
| #2 screw | 0.0860" | 0.0500" | 0.0250" | – |
| #3 screw | 0.0990" | 0.0370" | 0.0185" | – |
| #4 screw | 0.1120" | 0.0240" | 0.0120" | – |
| M3 bolt | 3 mm | 0.45 mm | 0.23 mm | Normal fit (normal 3.4, loose 3.6 mm) |
| #5 screw | 0.1250" | 0.0110" | 0.0055" | – |


## FAQ

**What size is a #29 drill?**
A #29 drill is 0.1360 in, which is 3.45 mm (3.4544 mm exactly).

**What is the metric equivalent of a #29 drill?**
The nearest metric drill is 3.5 mm, 0.046 mm larger. The other close size is 3.4 mm.

**What tap uses a #29 drill?**
A #29 drill is the standard tap drill for #8-32 UNC (about 69 % thread) and #8-36 UNF (about 78 % thread).

**Which fractional drill is closest to #29?**
9/64 in (0.1406 in) is the closest, 0.0046 in larger.

**What does a #29 drill clear?**
It clears a #5 screw with 0.0110" total clearance (0.0055" per side).

Source page: https://machinistcharts.com/drill-size/number-29/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)