Shop charts
Metric tap drills
ISO coarse + fine, M1–M24. Tap drill at 75% thread, 65% for hard material. All sizes in mm.
Lavigne Labs
Coarse M1.6 – M12 emphasised
| Size | Series | Pitch | Tap drill 75% | Hard mat. 65% | Clear close | Clear normal | Clear loose | SHCS c’bore | C’bore depth | FHCS c’sink |
|---|---|---|---|---|---|---|---|---|---|---|
| M1 | coarse | 0.25 | ⌀0.75 | ⌀0.8 | ⌀1.1 | ⌀1.2 | ⌀1.3 | — | — | — |
| M1.2 | coarse | 0.25 | ⌀0.95 | ⌀1.0 | ⌀1.3 | ⌀1.4 | ⌀1.5 | — | — | — |
| M1.4 | coarse | 0.3 | ⌀1.1 | ⌀1.15 | ⌀1.5 | ⌀1.6 | ⌀1.8 | — | — | — |
| M1.6 | coarse | 0.35 | ⌀1.25 | ⌀1.3 | ⌀1.7 | ⌀1.8 | ⌀2.0 | — | — | — |
| M1.8 | coarse | 0.35 | ⌀1.45 | ⌀1.5 | ⌀1.9 | ⌀2.0 | ⌀2.1 | — | — | — |
| M2 | coarse | 0.4 | ⌀1.6 | ⌀1.65 | ⌀2.2 | ⌀2.4 | ⌀2.6 | ⌀4.4 | 2 | — |
| M2.2 | coarse | 0.45 | ⌀1.75 | ⌀1.8 | ⌀2.4 | ⌀2.6 | ⌀2.8 | — | — | — |
| M2.5 | coarse | 0.45 | ⌀2.05 | ⌀2.1 | ⌀2.7 | ⌀2.9 | ⌀3.1 | ⌀5.4 | 2.5 | — |
| M3 | coarse | 0.5 | ⌀2.5 | ⌀2.6 | ⌀3.2 | ⌀3.4 | ⌀3.6 | ⌀6.5 | 3 | ⌀6.72 |
| M3.5 | coarse | 0.6 | ⌀2.9 | ⌀3.0 | ⌀3.7 | ⌀3.9 | ⌀4.2 | — | — | — |
| M4 | coarse | 0.7 | ⌀3.3 | ⌀3.4 | ⌀4.3 | ⌀4.5 | ⌀4.8 | ⌀8.25 | 4 | ⌀8.96 |
| M5 | coarse | 0.8 | ⌀4.2 | ⌀4.3 | ⌀5.3 | ⌀5.5 | ⌀5.8 | ⌀9.75 | 5 | ⌀11.2 |
| M6 | coarse | 1 | ⌀5.0 | ⌀5.2 | ⌀6.4 | ⌀6.6 | ⌀7.0 | ⌀11.2 | 6 | ⌀13.44 |
| M7 | coarse | 1 | ⌀6.0 | ⌀6.2 | ⌀7.4 | ⌀7.6 | ⌀8.0 | — | — | — |
| M8 | coarse | 1.25 | ⌀6.8 | ⌀6.9 | ⌀8.4 | ⌀9.0 | ⌀10.0 | ⌀14.5 | 8 | ⌀17.92 |
| M10 | coarse | 1.5 | ⌀8.5 | ⌀8.7 | ⌀10.5 | ⌀11.0 | ⌀12.0 | ⌀17.5 | 10 | ⌀22.4 |
| M12 | coarse | 1.75 | ⌀10.2 | ⌀10.5 | ⌀13.0 | ⌀13.5 | ⌀14.5 | ⌀19.5 | 12 | ⌀26.88 |
| M14 | coarse | 2 | ⌀12.0 | ⌀12.3 | ⌀15.0 | ⌀15.5 | ⌀16.5 | ⌀22.5 | 14 | ⌀30.8 |
| M16 | coarse | 2 | ⌀14.0 | ⌀14.3 | ⌀17.0 | ⌀17.5 | ⌀18.5 | ⌀25.5 | 16 | ⌀33.6 |
| M18 | coarse | 2.5 | ⌀15.5 | ⌀15.9 | ⌀19.0 | ⌀20.0 | ⌀21.0 | ⌀28.5 | 18 | — |
| M20 | coarse | 2.5 | ⌀17.5 | ⌀17.9 | ⌀21.0 | ⌀22.0 | ⌀24.0 | ⌀31.5 | 20 | ⌀40.32 |
| M22 | coarse | 2.5 | ⌀19.5 | ⌀19.9 | ⌀23.0 | ⌀24.0 | ⌀26.0 | — | — | — |
| M24 | coarse | 3 | ⌀21.0 | ⌀21.5 | ⌀25.0 | ⌀26.0 | ⌀28.0 | — | — | — |
Fine M1.6 – M12 emphasised
| Size | Series | Pitch | Tap drill 75% | Hard mat. 65% | Clear close | Clear normal | Clear loose | SHCS c’bore | C’bore depth | FHCS c’sink |
|---|---|---|---|---|---|---|---|---|---|---|
| M6 | fine | 0.75 | ⌀5.2 | ⌀5.4 | ⌀6.4 | ⌀6.6 | ⌀7.0 | ⌀11.2 | 6 | ⌀13.44 |
| M8 | fine | 1 | ⌀7.0 | ⌀7.2 | ⌀8.4 | ⌀9.0 | ⌀10.0 | ⌀14.5 | 8 | ⌀17.92 |
| M10 | fine | 1 | ⌀9.0 | ⌀9.2 | ⌀10.5 | ⌀11.0 | ⌀12.0 | ⌀17.5 | 10 | ⌀22.4 |
| M10 | fine | 1.25 | ⌀8.8 | ⌀8.9 | ⌀10.5 | ⌀11.0 | ⌀12.0 | ⌀17.5 | 10 | ⌀22.4 |
| M12 | fine | 1.25 | ⌀10.8 | ⌀10.9 | ⌀13.0 | ⌀13.5 | ⌀14.5 | ⌀19.5 | 12 | ⌀26.88 |
| M12 | fine | 1.5 | ⌀10.5 | ⌀10.7 | ⌀13.0 | ⌀13.5 | ⌀14.5 | ⌀19.5 | 12 | ⌀26.88 |
| M14 | fine | 1.5 | ⌀12.5 | ⌀12.7 | ⌀15.0 | ⌀15.5 | ⌀16.5 | ⌀22.5 | 14 | ⌀30.8 |
| M16 | fine | 1.5 | ⌀14.5 | ⌀14.7 | ⌀17.0 | ⌀17.5 | ⌀18.5 | ⌀25.5 | 16 | ⌀33.6 |
| M18 | fine | 1.5 | ⌀16.5 | ⌀16.7 | ⌀19.0 | ⌀20.0 | ⌀21.0 | ⌀28.5 | 18 | — |
| M20 | fine | 1.5 | ⌀18.5 | ⌀18.7 | ⌀21.0 | ⌀22.0 | ⌀24.0 | ⌀31.5 | 20 | ⌀40.32 |
| M20 | fine | 2 | ⌀18.0 | ⌀18.3 | ⌀21.0 | ⌀22.0 | ⌀24.0 | ⌀31.5 | 20 | ⌀40.32 |
| M22 | fine | 1.5 | ⌀20.5 | ⌀20.7 | ⌀23.0 | ⌀24.0 | ⌀26.0 | — | — | — |
| M24 | fine | 1.5 | ⌀22.5 | ⌀22.7 | ⌀25.0 | ⌀26.0 | ⌀28.0 | — | — | — |
| M24 | fine | 2 | ⌀22.0 | ⌀22.3 | ⌀25.0 | ⌀26.0 | ⌀28.0 | — | — | — |
| M12 | fine | 1 | ⌀11.0 | ⌀11.2 | ⌀13.0 | ⌀13.5 | ⌀14.5 | ⌀19.5 | 12 | ⌀26.88 |
| M14 | fine | 1.25 | ⌀12.8 | ⌀12.9 | ⌀15.0 | ⌀15.5 | ⌀16.5 | ⌀22.5 | 14 | ⌀30.8 |
| M16 | fine | 1 | ⌀15.0 | ⌀15.2 | ⌀17.0 | ⌀17.5 | ⌀18.5 | ⌀25.5 | 16 | ⌀33.6 |
| M18 | fine | 2 | ⌀16.0 | ⌀16.3 | ⌀19.0 | ⌀20.0 | ⌀21.0 | ⌀28.5 | 18 | — |
SHCS = socket head cap screw counterbore (diameter and depth). FHCS = flat head countersink diameter. “—” = no value listed.
How to use
How to pick a metric tap drill:
- Find the thread. Locate the screw size (for example M6) in the Size column and choose coarse or fine by its pitch.
- Read the tap drill. Use the Tap drill 75% column for the drill diameter in mm (M6 coarse: 5.0 mm).
- Adjust for hard material. For stainless steel or tool steel use the Hard mat. 65% column, which is slightly larger and easier on the tap.
- Drill, then tap. Drill the hole to the full thread depth plus a few threads, deburr it, then cut the thread with a tap lubricated for the material.
lavignelabs.net/tools/charts/metric-tap-drills/Lavigne Labs · verify against your own tooling before cutting