Technically reviewed by Vincent, Founder at HEXVARO
Last reviewed · Tables updated
Quick answer
Quick answer: common metric thread pitches
For the common sizes below, ISO 261:1998 / ISO 724:1993 coarse and fine pitch values and the reviewed tapping-chart recommendations are taken from the published rows below. M10 fine tapping is deliberately withheld because the two reviewed public charts round the recommended drill differently; resolve that tooling choice before release.
| Size | Coarse pitch / drill (mm) | Fine pitch / drill (mm) | Inquiry |
|---|---|---|---|
| M8 | 1.25 / 6.8 | 1.0 / 7.0 | Quote this size |
| M12 | 1.75 / 10.2 | 1.5 / 10.5 | Quote this size |
| M16 | 2.0 / 14.0 | 1.5 / 14.5 | Quote this size |
| M20 | 2.5 / 17.5 | 2.0 / 18.0 | Quote this size |
| M24 | 3.0 / 21.0 | 2.0 / 22.0 | Quote this size |
| M64 | 6.0 / 58.0 | 4.0 / 60.0 | Quote this size |
Sourcing these sizes? DIN 933 full-thread hex bolts Metric threaded rods
Metric coarse thread pitch and tapping drill chart
Reference basis: ISO 261:1998 and ISO 724:1993 for metric thread series, with the recommended drill values cross-checked against two public tapping charts. Drill values are recommendations, not a substitute for the tap maker's process data.
| Size | Coarse pitch P (mm) | Recommended tap drill (mm) | Inquiry |
|---|---|---|---|
| M3 | 0.5 | 2.5 | Quote this size |
| M4 | 0.7 | 3.3 | Quote this size |
| M5 | 0.8 | 4.2 | Quote this size |
| M6 | 1.0 | 5.0 | Quote this size |
| M8 | 1.25 | 6.8 | Quote this size |
| M10 | 1.5 | 8.5 | Quote this size |
| M12 | 1.75 | 10.2 | Quote this size |
| M14 | 2.0 | 12.0 | Quote this size |
| M16 | 2.0 | 14.0 | Quote this size |
| M18 | 2.5 | 15.5 | Quote this size |
| M20 | 2.5 | 17.5 | Quote this size |
| M22 | 2.5 | 19.5 | Quote this size |
| M24 | 3.0 | 21.0 | Quote this size |
| M27 | 3.0 | 24.0 | Quote this size |
| M30 | 3.5 | 26.5 | Quote this size |
| M33 | 3.5 | 29.5 | Quote this size |
| M36 | 4.0 | 32.0 | Quote this size |
| M39 | 4.0 | 35.0 | Quote this size |
| M42 | 4.5 | 37.5 | Quote this size |
| M45 | 4.5 | 40.5 | Quote this size |
| M48 | 5.0 | 43.0 | Quote this size |
| M52 | 5.0 | 47.0 | Quote this size |
| M56 | 5.5 | 50.5 | Quote this size |
| M60 | 5.5 | 54.5 | Quote this size |
| M64 | 6.0 | 58.0 | Quote this size |
Need these ISO 261:1998 / ISO 724:1993 / public tapping charts sizes? Request a quote
Metric fine thread pitch and tapping drill chart
Reference basis: ISO 261:1998 and ISO 724:1993. Fine-pitch rows below are published only where the reviewed sources agree on the recommended drill value. The M10 fine row is withheld pending manual resolution of the 8.75 mm versus 8.8 mm rounding difference; it is not an empty cell.
| Size | Fine pitch P (mm) | Recommended tap drill (mm) | Inquiry |
|---|---|---|---|
| M3 | 0.35 | 2.65 | Quote this size |
| M4 | 0.5 | 3.5 | Quote this size |
| M5 | 0.5 | 4.5 | Quote this size |
| M6 | 0.75 | 5.25 | Quote this size |
| M8 | 1.0 | 7.0 | Quote this size |
| M12 | 1.5 | 10.5 | Quote this size |
| M14 | 1.5 | 12.5 | Quote this size |
| M16 | 1.5 | 14.5 | Quote this size |
| M18 | 2.0 | 16.0 | Quote this size |
| M20 | 2.0 | 18.0 | Quote this size |
| M22 | 2.0 | 20.0 | Quote this size |
| M24 | 2.0 | 22.0 | Quote this size |
| M27 | 2.0 | 25.0 | Quote this size |
| M30 | 2.0 | 28.0 | Quote this size |
| M33 | 2.0 | 31.0 | Quote this size |
| M36 | 3.0 | 33.0 | Quote this size |
| M39 | 3.0 | 36.0 | Quote this size |
| M42 | 3.0 | 39.0 | Quote this size |
| M45 | 3.0 | 42.0 | Quote this size |
| M48 | 3.0 | 45.0 | Quote this size |
| M52 | 4.0 | 48.0 | Quote this size |
| M56 | 4.0 | 52.0 | Quote this size |
| M60 | 4.0 | 56.0 | Quote this size |
| M64 | 4.0 | 60.0 | Quote this size |
Need these ISO 261:1998 / ISO 724:1993 / public tapping charts sizes? Request a quote
Tapping callout checklist
- State the nominal size, pitch and tolerance class, for example M16 × 1.5 – 6H.
- State whether the hole is blind or through, the material, effective thread depth and the tap process.
- Use the recommended drill as a starting point and confirm the toolmaker's chart, coating, material and required thread percentage.
Tap drill and clearance hole by size
This table puts the tap drill beside the ISO 273 medium clearance hole, so one lookup covers both holes in a bolted joint.
| Size | Tap drill (mm) | Medium clearance (mm) | Inquiry |
|---|---|---|---|
| M3 | 2.5 | 3.4 | Quote this size |
| M4 | 3.3 | 4.5 | Quote this size |
| M5 | 4.2 | 5.5 | Quote this size |
| M6 | 5.0 | 6.6 | Quote this size |
| M8 | 6.8 | 9.0 | Quote this size |
| M10 | 8.5 | 11.0 | Quote this size |
| M12 | 10.2 | 13.5 | Quote this size |
| M14 | 12.0 | 15.5 | Quote this size |
| M16 | 14.0 | 17.5 | Quote this size |
| M18 | 15.5 | 20.0 | Quote this size |
| M20 | 17.5 | 22.0 | Quote this size |
| M22 | 19.5 | 24.0 | Quote this size |
| M24 | 21.0 | 26.0 | Quote this size |
| M27 | 24.0 | 30.0 | Quote this size |
| M30 | 26.5 | 33.0 | Quote this size |
| M33 | 29.5 | 36.0 | Quote this size |
| M36 | 32.0 | 39.0 | Quote this size |
Need these ISO 261:1998 / ISO 724:1993 / public tapping charts sizes? Request a quote
Order these sizes from HEXVARO
Send your size list with grade, finish and quantity — we reply within 2 working hours with price, lead time and shipping terms.
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- MOQ: 500 pcs per specification
- Lead time: 10–15 days stock items
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- Experience: Founder with 10+ years in the fastener industry
Frequently asked questions
What is the coarse pitch of an M16 thread?
The coarse-thread table lists M16 with a 2.0 mm pitch and a recommended 14.0 mm tapping drill.
What drill size is used for an M12 × 1.5 tap?
The fine-thread table lists M12 × 1.5 with a recommended 10.5 mm tapping drill.
What is the metric tap drill for M24 coarse thread?
The coarse table lists M24 with a 3.0 mm pitch and a recommended 21.0 mm tapping drill.
Why is the M10 fine tap-drill row withheld?
The two reviewed public charts give different rounded recommendations for the M10 fine case: 8.75 mm in one and 8.8 mm in the other. The page does not publish that unresolved row.
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