ISO Metric Coarse Thread Chart
36 thread sizes with dimensions calculated per ISO 724. Click any thread for detailed specifications.
See also: Metric Fine Thread Chart
| Thread | Pitch (mm) | Major Ø (mm) | Pitch Ø (mm) | Minor Ø (mm) | Tap Drill (mm) | Stress Area (mm²) |
|---|---|---|---|---|---|---|
| M1×0.25 | 0.25 | 1 | 0.838 | 0.693 | 0.7 | 0.4 |
| M1.2×0.25 | 0.25 | 1.2 | 1.038 | 0.893 | 0.9 | 0.7 |
| M1.4×0.3 | 0.3 | 1.4 | 1.205 | 1.032 | 1.1 | 0.9 |
| M1.6×0.35 | 0.35 | 1.6 | 1.373 | 1.171 | 1.2 | 1.2 |
| M1.8×0.35 | 0.35 | 1.8 | 1.573 | 1.371 | 1.4 | 1.6 |
| M2×0.4 | 0.4 | 2 | 1.74 | 1.509 | 1.6 | 2 |
| M2.5×0.45 | 0.45 | 2.5 | 2.208 | 1.948 | 2.0 | 3.3 |
| M3×0.5 | 0.5 | 3 | 2.675 | 2.386 | 2.5 | 4.9 |
| M3.5×0.6 | 0.6 | 3.5 | 3.11 | 2.764 | 2.9 | 6.6 |
| M4×0.7 | 0.7 | 4 | 3.545 | 3.141 | 3.2 | 8.5 |
| M5×0.8 | 0.8 | 5 | 4.48 | 4.019 | 4.1 | 13.8 |
| M6×1.0 | 1.0 | 6 | 5.351 | 4.773 | 5.0 | 19.6 |
| M7×1.0 | 1.0 | 7 | 6.351 | 5.773 | 6.0 | 28.2 |
| M8×1.25 | 1.25 | 8 | 7.188 | 6.466 | 6.8 | 35.6 |
| M9×1.25 | 1.25 | 9 | 8.188 | 7.466 | 7.5 | 47 |
| M10×1.5 | 1.5 | 10 | 9.026 | 8.16 | 8.5 | 56.5 |
| M12×1.75 | 1.75 | 12 | 10.863 | 9.853 | 10.2 | 82.2 |
| M14×2.0 | 2.0 | 14 | 12.701 | 11.546 | 12.0 | 112.7 |
| M16×2.0 | 2.0 | 16 | 14.701 | 13.546 | 14.0 | 153.5 |
| M18×2.5 | 2.5 | 18 | 16.376 | 14.933 | 15.5 | 188.1 |
| M20×2.5 | 2.5 | 20 | 18.376 | 16.933 | 17.5 | 239.8 |
| M22×2.5 | 2.5 | 22 | 20.376 | 18.933 | 19.5 | 297.9 |
| M24×3.0 | 3.0 | 24 | 22.052 | 20.319 | 20.5 | 345.3 |
| M27×3.0 | 3.0 | 27 | 25.052 | 23.319 | 24.0 | 451.2 |
| M30×3.5 | 3.5 | 30 | 27.727 | 25.706 | 26.0 | 550 |
| M33×3.5 | 3.5 | 33 | 30.727 | 28.706 | 29.0 | 681.8 |
| M36×4.0 | 4.0 | 36 | 33.402 | 31.092 | 32.0 | 802.2 |
| M39×4.0 | 4.0 | 39 | 36.402 | 34.092 | 35.0 | 959.8 |
| M42×4.5 | 4.5 | 42 | 39.077 | 36.479 | 38.0 | 1101.7 |
| M45×4.5 | 4.5 | 45 | 42.077 | 39.479 | 40.0 | 1285.3 |
| M48×5.0 | 5.0 | 48 | 44.752 | 41.865 | 42.0 | 1448.7 |
| M52×5.0 | 5.0 | 52 | 48.752 | 45.865 | 46.0 | 1731.1 |
| M56×5.5 | 5.5 | 56 | 52.428 | 49.252 | 50.0 | 1998.4 |
| M60×5.5 | 5.5 | 60 | 56.428 | 53.252 | 55.0 | 2327.9 |
| M64×6.0 | 6.0 | 64 | 60.103 | 56.639 | 58.0 | 2636.4 |
| M68×6.0 | 6.0 | 68 | 64.103 | 60.639 | 62.0 | 3013 |
About ISO Metric Coarse Threads
ISO metric coarse threads (ISO 261) are the default thread pitch for each nominal diameter. When a thread is specified as simply 'M10', it means M10 coarse (M10×1.5). Coarse threads are preferred for general-purpose fastening because they are more tolerant of minor damage and easier to assemble.
All dimensions are calculated using ISO 724 formulas. Pitch diameter: d₂ = d − 0.6495P. Minor diameter: d₁ = d − 1.2269P. Tap drill sizes are based on the internal minor diameter (D₁).