M6 tap drill size
Drill a 5.0 mm hole (0.1969") for an M6 × 1 tap. That leaves about 77% thread, the standard for general-purpose tapping.
M6 tap drill: 5.0 mm (0.1969 in / 5.00 mm), 77% threadM6 thread specs
| Series | ISO metric coarse |
|---|---|
| Major diameter | 6.00 mm (0.2362") |
| Pitch | 1 mm (25.4 TPI) |
| Basic minor diameter | 4.92 mm (0.1936") |
| Common internal class | 6H |
Every drill that works for M6
Drills from all four sets that give 50–85% thread, largest first. Lower percentages tap easier; see how much thread you need.
| Drill | Thread | in | mm | Set | Good for |
|---|---|---|---|---|---|
| #4 | 53% | 0.2090 | 5.31 | Number | deep holes only |
| 5.3 mm | 54% | 0.2087 | 5.30 | Metric | deep holes only |
| #5 | 60% | 0.2055 | 5.22 | Number | hard or tough metals |
| 5.2 mm | 62% | 0.2047 | 5.20 | Metric | hard or tough metals |
| #6 | 63% | 0.2040 | 5.18 | Number | hard or tough metals |
| 13/64" | 65% | 0.2031 | 5.16 | Fractional | hard or tough metals |
| #7 | 69% | 0.2010 | 5.11 | Number | hard or tough metals |
| 5.1 mm | 69% | 0.2008 | 5.10 | Metric | hard or tough metals |
| #8 | 73% | 0.1990 | 5.05 | Number | general use |
| 5.0 mmstandard | 77% | 0.1969 | 5.00 | Metric | general use |
| #9 | 79% | 0.1960 | 4.98 | Number | general use |
| #10 | 84% | 0.1935 | 4.91 | Number | more torque, more broken taps |
| 4.9 mm | 85% | 0.1929 | 4.90 | Metric | more torque, more broken taps |
M6 clearance hole
The hole a M6 screw passes through. ISO 273 fine, medium and coarse series.
| Fit | mm | in |
|---|---|---|
| Close (fine) | 6.4 mm | 0.2520 |
| Normal (medium) | 6.6 mm | 0.2598 |
| Loose (coarse) | 7.0 mm | 0.2756 |
M6 counterbore and countersink
For a socket head cap screw to sit flush, and for a flat head socket screw.
| Socket head counterbore | Diameter | Depth |
|---|---|---|
| NBK | 11.00 mm | 6.50 mm |
| AMES | 11.25 mm | 6.00 mm |
Flat head socket screw: countersink at 90° (metric screws, ISO 10642) to 13.44 mm (0.5291") across for a flush head. Inch flat heads use 82°, so don't mix countersinks.
M6 heat-set insert hole
Hole to model for a brass heat-set insert in a 3D print. Brands size their knurl differently, so use your brand’s number.
| Brand | Hole |
|---|---|
| CNC Kitchen | 8.00 mm |
| Accu | 8.00 mm |
| Generic (Albany County) | 7.60 mm |
M6 holes in a 3D print
Printed holes usually come out undersize. Model the hole at the drill size plus what your printer loses, then tap or drill to size. Why printed holes shrink.
Print a test hole, measure it with calipers, enter the difference. 0 models the nominal size.
M6 thread repair (Helicoil)
Stripped M6 thread? Drill out with the STI drill, tap with a M6 × 1 STI tap, and fit a wire thread insert. The drill in your repair kit’s instructions wins over any chart.
| Chart | STI drill | in | mm |
|---|---|---|---|
| MISUMI | 6.2 mm | 0.2441 | 6.20 |
Related sizes
Frequently asked questions
What size drill do I use for an M6 tap?
What inch drill can I use for an M6 tap?
What size clearance hole for an M6 screw?
What hole size for an M6 heat-set insert?
What is the inch equivalent of M6?
Sources
- Engineers Edge: metric ISO tap drill chart checked 2026-10-19
- Penn MEDesign: tap drill chart checked 2026-10-19
- Albany County Fasteners: clearance hole chart (PDF) checked 2026-10-19
- AMES: metric clearance hole chart (ASME B18.2.8) checked 2026-10-19
- NBK: dimensions of holes for hexagon socket head cap screws checked 2026-10-19
- AMES: counterbore hole dimensions, metric (Machinery's Handbook) checked 2026-10-19
- Global Fastener: ISO 10642 hexagon socket countersunk head screws checked 2026-10-19
- Eugene Fastener: flat head socket screw countersink guide checked 2026-10-19
- SC Fastening: flat head socket cap screw spec, ASME B18.3 (PDF) checked 2026-10-19
- CNC Kitchen threaded inserts (3DJake listing, hole diameter D3) checked 2026-10-19
- Accu: threaded insert hole size charts for 3D printing checked 2026-10-19
- Albany County Fasteners: heat-set insert specs (PDF) checked 2026-10-19
- MISUMI: Helicoil tap and drill size chart checked 2026-10-19
Spotted a wrong number? Email contact@clove3d.com and it gets fixed.
% thread = (major − drill) ÷ (1.299 × pitch) × 100. The standard drill comes from published charts and is checked against this formula on every build.