Specification summary of ISO 7042 as applied to all-metal lock nuts: the dimensions the standard controls, the full specified size range, and the equivalent DIN/ISO/ASME designations.
ISO 7042 — Scope
ISO 7042 is "Prevailing torque type all-metal hexagon high nuts (style 2)".
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
ISO 7042 does not divide all-metal lock nuts into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by ISO 7042
| 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 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent All-Metal Lock Nuts page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
ISO 7042 controls only the geometry of all-metal lock nuts. The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
Custom manufacturing · Made to drawing
Need a nut to this standard in a non-standard size?
Parts built to ISO 7042 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

