Metric Clearance Hole and Tap Drill Chart
66 controlled metric diameter references
1979 / 1972 · Current Reference · ThreadClearance values are direct ISO 273:1979 table lookups. Tap-drill values are direct ISO 2306:1972 table lookups for conventional tapping and normal engagement.
ISO 273 / ISO 2306 dimensions
| Thread | Coarse P (mm) | Tap drill (mm) | Fine H12 (mm) | Medium H13 (mm) | Coarse H14 (mm) |
|---|---|---|---|---|---|
| M1 | 0.25 | 0.75 | 1.1 | 1.2 | 1.3 |
| M1.1 | 0.25 | 0.85 | — | — | — |
| M1.2 | 0.25 | 0.95 | 1.3 | 1.4 | 1.5 |
| M1.4 | 0.3 | 1.1 | 1.5 | 1.6 | 1.8 |
| M1.6 | 0.35 | 1.25 | 1.7 | 1.8 | 2 |
| M1.8 | 0.35 | 1.45 | 2 | 2.1 | 2.2 |
| M2 | 0.4 | 1.6 | 2.2 | 2.4 | 2.6 |
| M2.2 | 0.45 | 1.75 | — | — | — |
| M2.5 | 0.45 | 2.05 | 2.7 | 2.9 | 3.1 |
| M3 | 0.5 | 2.5 | 3.2 | 3.4 | 3.6 |
| M3.5 | 0.6 | 2.9 | 3.7 | 3.9 | 4.2 |
| M4 | 0.7 | 3.3 | 4.3 | 4.5 | 4.8 |
| M4.5 | 0.75 | 3.7 | 4.8 | 5 | 5.3 |
| M5 | 0.8 | 4.2 | 5.3 | 5.5 | 5.8 |
| M5.5 | — | — | — | — | — |
| M6 | 1 | 5 | 6.4 | 6.6 | 7 |
| M7 | 1 | 6 | 7.4 | 7.6 | 8 |
| M8 | 1.25 | 6.8 | 8.4 | 9 | 10 |
| M9 | 1.25 | 7.8 | — | — | — |
| M10 | 1.5 | 8.5 | 10.5 | 11 | 12 |
| M11 | 1.5 | 9.5 | — | — | — |
| M12 | 1.75 | 10.2 | 13 | 13.5 | 14.5 |
| M14 | 2 | 12 | 15 | 15.5 | 16.5 |
| M15 | — | — | — | — | — |
| M16 | 2 | 14 | 17 | 17.5 | 18.5 |
| M17 | — | — | — | — | — |
| M18 | 2.5 | 15.5 | 19 | 20 | 21 |
| M20 | 2.5 | 17.5 | 21 | 22 | 24 |
| M22 | 2.5 | 19.5 | 23 | 24 | 26 |
| M24 | 3 | 21 | 25 | 26 | 28 |
| M25 | — | — | — | — | — |
| M26 | — | — | — | — | — |
| M27 | 3 | 24 | 28 | 30 | 32 |
| M28 | — | — | — | — | — |
| M30 | 3.5 | 26.5 | 31 | 33 | 35 |
| M32 | — | — | — | — | — |
| M33 | 3.5 | 29.5 | 34 | 36 | 38 |
| M35 | — | — | — | — | — |
| M36 | 4 | 32 | 37 | 39 | 42 |
| M38 | — | — | — | — | — |
| M39 | 4 | 35 | 40 | 42 | 45 |
| M40 | — | — | — | — | — |
| M42 | 4.5 | 37.5 | 43 | 45 | 48 |
| M45 | 4.5 | 40.5 | 46 | 48 | 52 |
| M48 | 5 | 43 | 50 | 52 | 56 |
| M50 | — | — | — | — | — |
| M52 | 5 | 47 | 54 | 56 | 62 |
| M56 | 5.5 | 50.5 | 58 | 62 | 66 |
| M60 | — | — | 62 | 66 | 70 |
| M64 | — | — | 66 | 70 | 74 |
| M68 | — | — | 70 | 74 | 78 |
| M72 | — | — | 74 | 78 | 82 |
| M76 | — | — | 78 | 82 | 86 |
| M80 | — | — | 82 | 86 | 91 |
| M85 | — | — | 87 | 91 | 96 |
| M90 | — | — | 93 | 96 | 101 |
| M95 | — | — | 98 | 101 | 107 |
| M100 | — | — | 104 | 107 | 112 |
| M105 | — | — | 109 | 112 | 117 |
| M110 | — | — | 114 | 117 | 122 |
| M115 | — | — | 119 | 122 | 127 |
| M120 | — | — | 124 | 127 | 132 |
| M125 | — | — | 129 | 132 | 137 |
| M130 | — | — | 134 | 137 | 144 |
| M140 | — | — | 144 | 147 | 155 |
| M150 | — | — | 155 | 158 | 165 |
66 of 66 sizes shown.
Jump to a metric diameterM1M1.1M1.2M1.4M1.6M1.8M2M2.2M2.5M3M3.5M4
Clearance-hole source: ISO 273:1979 — Fine H12, medium H13 and coarse H14 series for general-purpose bolt and screw clearance holes.
Tap-drill source: ISO 2306:1972 — Coarse- and fine-pitch table values for drilling before conventional tapping.
Selection boundary: Confirm the application — Special clearance holes follow design requirements. Tap-drill choice can change with material, tool geometry, alignment, feed and speed.