Standards and grades
DIN 985 and ISO 7040 prevailing torque nut: sizes and equivalents
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DIN 985 is the hex prevailing torque nut with a non-metallic insert: the insert grips the bolt threads and resists loosening from vibration. It is a withdrawn DIN standard, but it is still ordered under that name.
Most catalogues cross it with ISO 10511. ISO 7040 is another prevailing torque nut with a non-metallic insert from the ISO series, so before swapping one for the other, compare the height and the across flats with what the drawing requires.
| Standard | What it is |
|---|---|
| DIN 985 | Prevailing torque nut with non-metallic insert, withdrawn DIN standard |
| ISO 10511 | ISO equivalent that most catalogues cross it with |
| ISO 7040 | Prevailing torque nut with non-metallic insert from the ISO series |
DIN 985 dimensions from M6 to M24
| Thread size | Pitch | Across flats s | Maximum height |
|---|---|---|---|
| M6 | 1 | 10 | 6 |
| M8 | 1.25 | 13 | 8 |
| M10 | 1.5 | 17 | 10 |
| M12 | 1.75 | 19 | 12 |
| M16 | 2 | 24 | 16 |
| M20 | 2.5 | 30 | 20 |
| M24 | 3 | 36 | 24 |
Values in millimetres according to DIN 985 (1987 edition). Supplied to order.