# M48 tap drill size

The tap drill for an M48 × 5 metric coarse thread is 43 mm (1.6929 in). It leaves about 77 % thread, the normal range for steel.

## Drill options for M48 × 5

| Drill | Inch | Thread % |
|---|---|---|
| 42.8 mm | 1.6850 | 80 % |
| 42.9 mm | 1.6890 | 79 % |
| 43 mm | 1.6929 | 77 % |
| 43.1 mm | 1.6969 | 75 % |
| 43.2 mm | 1.7008 | 74 % |

## M48 thread data

- Thread: M48 × 5 (coarse)
- Pitch: 5 mm
- Tap drill: 43 mm (1.6929 in)
- Thread engagement: 77 %
- Clearance hole (ISO 273): 50 close, 52 normal, 56 loose (mm)

## Method

Thread % = 76.98 × (D − drill) / P = 76.98 × 5 / 5 = 77 %. Aim for 65–75 % in steel, 75–85 % in aluminium, brass and plastics.

## FAQ

**What size drill for an M48 × 5 tap?**
Use a 43 mm drill. It leaves about 77 % thread engagement.

**What is 43 mm in inches?**
43 mm is 1.6929 inch.

**What size clearance hole for M48?**
ISO 273 gives 50 mm for a close fit, 52 mm normal and 56 mm loose.

Source page: https://machinistcharts.com/tap-drill/m48/
Updated: 2026-10-05
Publisher: MachinistCharts (https://machinistcharts.com)