Bolt thread dimensions.
Metric and inch thread geometry plus practical bolt-head, nut and washer dimensions used when checking an industrial fastener enquiry.
Thread calculation: theoretical basic-profile values are useful for selection and quoting. Manufacturing limits, coating allowance and tolerance class must follow the current governing standard.
One size.
Several dimensions.
The table combines common ISO metric coarse pitch with ISO 4014/4017 head width/height, ISO 4032 nut height and ISO 7089 normal-series washer dimensions for quick procurement reference.
| Size | Pitch P | Stress area | Tap drill* | Bolt head s | Head k | Nut m | Washer d1 | Washer d2 | Washer s |
|---|---|---|---|---|---|---|---|---|---|
| M3 | 0.5 mm | 5.0 mm² | 2.5 mm | 5.5 mm | 2 mm | 2.4 mm | 3.2 mm | 7 mm | 0.5 mm |
| M4 | 0.7 mm | 8.8 mm² | 3.3 mm | 7 mm | 2.8 mm | 3.2 mm | 4.3 mm | 9 mm | 0.8 mm |
| M5 | 0.8 mm | 14.2 mm² | 4.2 mm | 8 mm | 3.5 mm | 4.7 mm | 5.3 mm | 10 mm | 1 mm |
| M6 | 1 mm | 20.1 mm² | 5.0 mm | 10 mm | 4 mm | 5.2 mm | 6.4 mm | 12 mm | 1.6 mm |
| M8 | 1.25 mm | 36.6 mm² | 6.8 mm | 13 mm | 5.3 mm | 6.8 mm | 8.4 mm | 16 mm | 1.6 mm |
| M10 | 1.5 mm | 58.0 mm² | 8.5 mm | 16 mm | 6.4 mm | 8.4 mm | 10.5 mm | 20 mm | 2 mm |
| M12 | 1.75 mm | 84.3 mm² | 10.3 mm | 18 mm | 7.5 mm | 10.8 mm | 13 mm | 24 mm | 2.5 mm |
| M14 | 2 mm | 115.4 mm² | 12.0 mm | 21 mm | 8.8 mm | 12.8 mm | 15 mm | 28 mm | 2.5 mm |
| M16 | 2 mm | 156.7 mm² | 14.0 mm | 24 mm | 10 mm | 14.8 mm | 17 mm | 30 mm | 3 mm |
| M18 | 2.5 mm | 192.5 mm² | 15.5 mm | 27 mm | 11.5 mm | 15.8 mm | 19 mm | 34 mm | 3 mm |
| M20 | 2.5 mm | 244.8 mm² | 17.5 mm | 30 mm | 12.5 mm | 18 mm | 21 mm | 37 mm | 3 mm |
| M22 | 2.5 mm | 303.4 mm² | 19.5 mm | 34 mm | 14 mm | 19.4 mm | 23 mm | 39 mm | 3 mm |
| M24 | 3 mm | 352.5 mm² | 21.0 mm | 36 mm | 15 mm | 21.5 mm | 25 mm | 44 mm | 4 mm |
| M27 | 3 mm | 459.4 mm² | 24.0 mm | 41 mm | 17 mm | 23.8 mm | 28 mm | 50 mm | 4 mm |
| M30 | 3.5 mm | 560.6 mm² | 26.5 mm | 46 mm | 18.7 mm | 25.6 mm | 31 mm | 56 mm | 4 mm |
| M33 | 3.5 mm | 693.6 mm² | 29.5 mm | 50 mm | 21 mm | 28.7 mm | 34 mm | 60 mm | 5 mm |
| M36 | 4 mm | 816.7 mm² | 32.0 mm | 55 mm | 22.5 mm | 31 mm | 37 mm | 66 mm | 5 mm |
| M39 | 4 mm | 975.8 mm² | 35.0 mm | 60 mm | 25 mm | 33.4 mm | 42 mm | 72 mm | 6 mm |
| M42 | 4.5 mm | 1,120.9 mm² | 37.5 mm | 65 mm | 26 mm | 34 mm | 45 mm | 78 mm | 8 mm |
| M45 | 4.5 mm | 1,306.0 mm² | 40.5 mm | 70 mm | 28 mm | 36 mm | 48 mm | 85 mm | 8 mm |
| M48 | 5 mm | 1,473.1 mm² | 43.0 mm | 75 mm | 30 mm | 38 mm | 52 mm | 92 mm | 8 mm |
| M52 | 5 mm | 1,757.8 mm² | 47.0 mm | 80 mm | 33 mm | 42 mm | 56 mm | 98 mm | 8 mm |
| M56 | 5.5 mm | 2,030.0 mm² | 50.5 mm | 85 mm | 35 mm | 45 mm | 62 mm | 105 mm | 10 mm |
| M60 | 5.5 mm | 2,362.0 mm² | 54.5 mm | 90 mm | 38 mm | 48 mm | 66 mm | 110 mm | 10 mm |
| M64 | 6 mm | 2,676.0 mm² | 58.0 mm | 95 mm | 40 mm | 51 mm | 70 mm | 115 mm | 10 mm |
*Approximate coarse-thread tap-drill starting reference (major diameter − pitch), not a machining instruction. Confirm tool supplier recommendation, material and tolerance class.
Hex bolt dimensions
Hex nut dimensions
Check the wrench size.
Some legacy DIN hex sizes use different across-flats dimensions from the ISO replacement. This matters when replacing existing fasteners or matching restricted tool access.
| Nominal size | Legacy DIN 931/933 s | ISO 4014/4017 s | Procurement note |
|---|---|---|---|
| M10 | 17 mm | 16 mm | Do not assume the existing wrench/head envelope is unchanged. |
| M12 | 19 mm | 18 mm | Legacy stock and ISO stock can differ visibly. |
| M14 | 22 mm | 21 mm | Confirm the drawing or replacement requirement. |
| M22 | 32 mm | 34 mm | ISO is larger across flats in this size. |