An M10 Class 12.9 bolt takes 84.4 N·m (62.3 ft·lbs) dry, or 63.3 N·m oiled. Every size from M3 to M64 is listed below — click a value for the full spec including all six surface conditions and fine-thread figures.
| Size | Pitch | N·m (dry) | ft·lbs (dry) | N·m (oiled) |
|---|---|---|---|---|
| M3 | 0.5 mm | 2.2 | 1.6 | 1.6 |
| M4 | 0.7 mm | 5.1 | 3.8 | 3.8 |
| M5 | 0.8 mm | 10.3 | 7.6 | 7.7 |
| M6 | 1.0 mm | 17.6 | 13.0 | 13.2 |
| M7 | 1.0 mm | 29.4 | 21.7 | 22.0 |
| M8 | 1.25 mm | 42.6 | 31.4 | 32.0 |
| M10 | 1.5 mm | 84.4 | 62.3 | 63.3 |
| M12 | 1.75 mm | 147.1 | 108.5 | 110.4 |
| M14 | 2.0 mm | 235.2 | 173.5 | 176.4 |
| M16 | 2.0 mm | 364.7 | 269.0 | 273.5 |
| M18 | 2.5 mm | 504.1 | 371.8 | 378.1 |
| M20 | 2.5 mm | 712.3 | 525.4 | 534.3 |
| M22 | 2.5 mm | 971.2 | 716.3 | 728.4 |
| M24 | 3.0 mm | 1230.9 | 907.9 | 923.2 |
| M27 | 3.0 mm | 1804.8 | 1331.2 | 1353.6 |
| M30 | 3.5 mm | 2447.0 | 1804.8 | 1835.2 |
| M33 | 3.5 mm | 3330.1 | 2456.2 | 2497.6 |
| M36 | 4.0 mm | 4278.0 | 3155.3 | 3208.5 |
| M39 | 4.0 mm | 5538.3 | 4084.8 | 4153.7 |
| M42 | 4.5 mm | 6849.8 | 5052.2 | 5137.4 |
| M45 | 4.5 mm | 8551.6 | 6307.3 | 6413.7 |
| M48 | 5.0 mm | 10288.8 | 7588.6 | 7716.6 |
| M52 | 5.0 mm | 13299.0 | 9808.8 | 9974.2 |
| M56 | 5.5 mm | 16540.4 | 12199.6 | 12405.3 |
| M64 | 6.0 mm | 24918.9 | 18379.2 | 18689.2 |
Dry/plain steel, K = 0.20 · Coarse thread · Clamp load 75% of proof load · Click any N·m value for full details
Identification: Head stamped 12.9. The two-part number is the strength code: 1,220 MPa tensile, 1,100 MPa yield.
Material: Alloy steel, quenched and tempered, proof stress 970 MPa per ISO 898-1.
Where it is used: The highest common metric class — socket head cap screws, tooling, dies, motorsport and compact high-load assemblies.
Worth knowing: Class 12.9 is strong but notch-sensitive and more prone to hydrogen embrittlement when plated. It is usually supplied black oxide or plain rather than zinc plated.
Every figure comes from T = K × D × F, where K is the nut factor (0.20 dry, 0.15 oiled), D is nominal diameter in metres, and F is clamp load set at 75% of proof load. Proof stress and tensile stress area come from ISO 898-1.
These are engineering reference values for a standard hex bolt in a steel joint. Where a manufacturer publishes a specific figure, use theirs. Full methodology →
It depends on diameter. An M8 Class 12.9 takes 42.6 N·m (31.4 ft·lbs), an M10 takes 84.4 N·m (62.3 ft·lbs), and an M12 takes 147.1 N·m (108.5 ft·lbs) — all dry, plain steel, coarse thread. The full table covers M3 to M64.
The first number is one hundredth of the minimum tensile strength in MPa, and the second is ten times the ratio of yield to tensile strength. So 12.9 means 1,220 MPa tensile and a yield point at 90% of that — 1,100 MPa.
Alloy steel, quenched and tempered, with a minimum tensile strength of 1,220 MPa, yield strength of 1,100 MPa and proof stress of 970 MPa per ISO 898-1.
Yes. Oil lowers the nut factor from about 0.20 to 0.15, so the same clamp load needs roughly 25% less torque. An M10 Class 12.9 goes from 84.4 N·m dry to 63.3 N·m oiled — using the dry figure on an oiled bolt risks exceeding yield.