# M3x0.35 tap drill size

The tap drill for an M3 × 0.35 metric fine thread is 2.65 mm (0.1043 in). It leaves about 77 % thread, the normal range for steel.

## Drill options for M3 × 0.35

| Drill | Inch | Thread % |
|---|---|---|
| 2.55 mm | 0.1004 | 99 % |
| 2.65 mm | 0.1043 | 77 % |
| 2.75 mm | 0.1083 | 55 % |

## M3x0.35 thread data

- Thread: M3 × 0.35 (fine)
- Pitch: 0.35 mm
- Tap drill: 2.65 mm (0.1043 in)
- Thread engagement: 77 %
- Clearance hole (ISO 273): 3.2 close, 3.4 normal, 3.6 loose (mm)

## Method

Thread % = 76.98 × (D − drill) / P = 76.98 × 0.35 / 0.35 = 77 %. Aim for 65–75 % in steel, 75–85 % in aluminium, brass and plastics.

## FAQ

**What size drill for an M3 × 0.35 tap?**
Use a 2.65 mm drill. It leaves about 77 % thread engagement.

**What is 2.65 mm in inches?**
2.65 mm is 0.1043 inch.

**What size clearance hole for M3?**
ISO 273 gives 3.2 mm for a close fit, 3.4 mm normal and 3.6 mm loose.

Source page: https://machinistcharts.com/tap-drill/m3x0-35/
Updated: 2026-10-05
Publisher: MachinistCharts (https://machinistcharts.com)