Specification summary of DIN 980 as applied to all-metal lock nuts: the dimensions the standard controls, the tolerance and product grades it defines, the full specified size range, and the equivalent DIN/ISO/ASME designations.
DIN 980 — Scope
DIN 980 specifies the dimensions and tolerances of all-metal lock nuts. Material, property class, surface finish and packaging are governed by separate documents in the same standards family (for example ISO 898-1 for the mechanical property classes of bolts and screws).
Tolerance & Product Grades
DIN 980, alongside the related ISO 7042 / DIN 980 entries on this site, specifies product grades (typically A or B for fine work and C for general engineering) and tolerance classes for the controlling dimensions. Choose the grade against the precision your application requires.
Dimensions Specified by DIN 980
| Size | Pitch (mm) | Width across flats s (mm) | Nut height m (mm) | Reference standard | Notes |
|---|---|---|---|---|---|
| M5 | 0.8 | 8.0 | 6.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M6 | 1.0 | 10.0 | 7.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M8 | 1.25 | 13.0 | 9.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M10 | 1.5 | 16.0 | 11.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M12 | 1.75 | 18.0 | 13.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M14 | 2.0 | 21.0 | 15.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M16 | 2.0 | 24.0 | 17.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M18 | 2.5 | 27.0 | 19.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M20 | 2.5 | 30.0 | 21.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M24 | 3.0 | 36.0 | 24.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M30 | 3.5 | 46.0 | 30.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
| M36 | 4.0 | 55.0 | 36.0 | ISO 7042 / DIN 980 | Deformed-top locking, high-temperature capable |
Companion Standards
DIN 980 controls only the geometry of all-metal lock nuts. The mechanical strength is set by ISO 898-1 (bolts and screws) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards (e.g. ISO 4042 for electroplating). For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
When to Specify DIN 980
DIN 980 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.

