Reference & Charts
Metric Drill Size Chart
The standard metric twist-drill stock series from 0.5 mm to 13 mm with the decimal-inch equivalent for each. These are true metric drills (3.0, 3.2, 3.5 mm…), not the millimetre conversions of inch drills — search a size to convert or compare.
66 entries · Last verified: 2026-07-17
Metric drills are a separate stock series from the inch (fractional / number / letter) drills — a metric hole calls for a metric drill, not the nearest inch size. This chart lists the common metric stock sizes and their exact decimal-inch equivalent (millimetre ÷ 25.4) so you can convert, compare, or find the nearest available drill.
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| Drill | Size(mm) | Decimal inch(in) |
|---|---|---|
| 0.5 mm | 0.5 mm | 0.0197 in |
| 0.6 mm | 0.6 mm | 0.0236 in |
| 0.7 mm | 0.7 mm | 0.0276 in |
| 0.8 mm | 0.8 mm | 0.0315 in |
| 0.9 mm | 0.9 mm | 0.0354 in |
| 1 mm | 1 mm | 0.0394 in |
| 1.1 mm | 1.1 mm | 0.0433 in |
| 1.2 mm | 1.2 mm | 0.0472 in |
| 1.3 mm | 1.3 mm | 0.0512 in |
| 1.4 mm | 1.4 mm | 0.0551 in |
| 1.5 mm | 1.5 mm | 0.0591 in |
| 1.6 mm | 1.6 mm | 0.063 in |
| 1.7 mm | 1.7 mm | 0.0669 in |
| 1.8 mm | 1.8 mm | 0.0709 in |
| 1.9 mm | 1.9 mm | 0.0748 in |
| 2 mm | 2 mm | 0.0787 in |
| 2.1 mm | 2.1 mm | 0.0827 in |
| 2.2 mm | 2.2 mm | 0.0866 in |
| 2.3 mm | 2.3 mm | 0.0906 in |
| 2.4 mm | 2.4 mm | 0.0945 in |
| 2.5 mm | 2.5 mm | 0.0984 in |
| 2.6 mm | 2.6 mm | 0.1024 in |
| 2.7 mm | 2.7 mm | 0.1063 in |
| 2.8 mm | 2.8 mm | 0.1102 in |
| 2.9 mm | 2.9 mm | 0.1142 in |
| 3 mm | 3 mm | 0.1181 in |
| 3.1 mm | 3.1 mm | 0.122 in |
| 3.2 mm | 3.2 mm | 0.126 in |
| 3.3 mm | 3.3 mm | 0.1299 in |
| 3.4 mm | 3.4 mm | 0.1339 in |
| 3.5 mm | 3.5 mm | 0.1378 in |
| 3.6 mm | 3.6 mm | 0.1417 in |
| 3.7 mm | 3.7 mm | 0.1457 in |
| 3.8 mm | 3.8 mm | 0.1496 in |
| 3.9 mm | 3.9 mm | 0.1535 in |
| 4 mm | 4 mm | 0.1575 in |
| 4.1 mm | 4.1 mm | 0.1614 in |
| 4.2 mm | 4.2 mm | 0.1654 in |
| 4.3 mm | 4.3 mm | 0.1693 in |
| 4.4 mm | 4.4 mm | 0.1732 in |
| 4.5 mm | 4.5 mm | 0.1772 in |
| 4.6 mm | 4.6 mm | 0.1811 in |
| 4.7 mm | 4.7 mm | 0.185 in |
| 4.8 mm | 4.8 mm | 0.189 in |
| 4.9 mm | 4.9 mm | 0.1929 in |
| 5 mm | 5 mm | 0.1969 in |
| 5.1 mm | 5.1 mm | 0.2008 in |
| 5.2 mm | 5.2 mm | 0.2047 in |
| 5.3 mm | 5.3 mm | 0.2087 in |
| 5.4 mm | 5.4 mm | 0.2126 in |
| 5.5 mm | 5.5 mm | 0.2165 in |
| 6 mm | 6 mm | 0.2362 in |
| 6.5 mm | 6.5 mm | 0.2559 in |
| 7 mm | 7 mm | 0.2756 in |
| 7.5 mm | 7.5 mm | 0.2953 in |
| 8 mm | 8 mm | 0.315 in |
| 8.5 mm | 8.5 mm | 0.3346 in |
| 9 mm | 9 mm | 0.3543 in |
| 9.5 mm | 9.5 mm | 0.374 in |
| 10 mm | 10 mm | 0.3937 in |
| 10.5 mm | 10.5 mm | 0.4134 in |
| 11 mm | 11 mm | 0.4331 in |
| 11.5 mm | 11.5 mm | 0.4528 in |
| 12 mm | 12 mm | 0.4724 in |
| 12.5 mm | 12.5 mm | 0.4921 in |
| 13 mm | 13 mm | 0.5118 in |
Frequently asked
- Are these different from the millimetre column on the inch drill chart?
- Yes. The inch Drill Size Chart's millimetre column is just the conversion of an inch-defined drill (e.g. a #7 drill is 0.201" = 5.11 mm). These are the real metric stock drills you'd actually order — 5.0 mm, 5.1 mm, 5.5 mm, and so on.
- How do I convert a metric drill to inches?
- Divide the millimetre size by 25.4. A 6.5 mm drill is 6.5 ÷ 25.4 ≈ 0.256". Every row here lists that value so you don't have to.
- Is every metric size made?
- This is the common stock range (0.5–13 mm, in 0.1 mm steps up to 5.5 mm then 0.5 mm steps). Finer increments and larger sizes exist; check availability for anything outside this range or with a tight tolerance.
Sources
- Standard metric twist-drill stock sizes (ISO 235 series / common jobber stock)
- Inch equivalents computed as millimetres ÷ 25.4