Specification summary of ISO 7980 as applied to spring lock washers: the dimensions the standard fixes, the full size range supplied, and the related designations commonly cross-referenced.
ISO 7980 — Scope
ISO 7980 specifies the dimensional requirements for spring lock washers. Material, surface condition and any performance rating are set by separate documents specific to this part family — ISO 898-1 and ISO 898-2, which govern bolt and nut property classes, do not apply here.
Tolerance & Product Grades
Tolerances for spring lock washers are given as limits on the individual dimensions in the table rather than as a fastener product grade. Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by ISO 7980
| For bolt size | Inner diameter d1 min (mm) | Outer diameter d2 max (mm) | Width b (mm) | Thickness s (mm) | Reference standard |
|---|---|---|---|---|---|
| M2 | 2.1 | 4.4 | 1.6 | 0.5 | ISO 7980 / DIN 127 |
| M2.5 | 2.6 | 5.1 | 2.0 | 0.6 | ISO 7980 / DIN 127 |
| M3 | 3.1 | 6.2 | 2.0 | 0.8 | ISO 7980 / DIN 127 |
| M3.5 | 3.6 | 7.0 | 2.5 | 0.8 | ISO 7980 / DIN 127 |
| M4 | 4.1 | 7.6 | 2.5 | 1.0 | ISO 7980 / DIN 127 |
| M5 | 5.1 | 9.2 | 3.0 | 1.2 | ISO 7980 / DIN 127 |
| M6 | 6.1 | 11.8 | 4.0 | 1.6 | ISO 7980 / DIN 127 |
| M7 | 7.1 | 13.1 | 4.0 | 1.6 | ISO 7980 / DIN 127 |
| M8 | 8.1 | 14.8 | 5.0 | 2.0 | ISO 7980 / DIN 127 |
| M10 | 10.2 | 18.1 | 6.0 | 2.2 | ISO 7980 / DIN 127 |
| M12 | 12.2 | 21.1 | 7.0 | 2.5 | ISO 7980 / DIN 127 |
| M14 | 14.2 | 24.1 | 8.0 | 3.0 | ISO 7980 / DIN 127 |
| M16 | 16.2 | 27.4 | 9.0 | 3.5 | ISO 7980 / DIN 127 |
| M18 | 18.2 | 29.4 | 9.0 | 3.5 | ISO 7980 / DIN 127 |
| M20 | 20.2 | 33.6 | 10.0 | 4.0 | ISO 7980 / DIN 127 |
| M22 | 22.5 | 35.9 | 11.0 | 4.0 | ISO 7980 / DIN 127 |
| M24 | 24.5 | 40.1 | 12.0 | 5.0 | ISO 7980 / DIN 127 |
| M27 | 27.5 | 44.8 | 12.0 | 5.0 | ISO 7980 / DIN 127 |
| M30 | 30.5 | 50.0 | 14.0 | 6.0 | ISO 7980 / DIN 127 |
| M36 | 36.5 | 60.0 | 16.0 | 7.0 | ISO 7980 / DIN 127 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Spring Lock Washers page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
ISO 7980 controls only the geometry of spring lock washers. Surface finish is governed by separate finish standards (for example ISO 4042 for electroplating), and corrosion testing by ISO 9227 (neutral salt spray). Mechanical performance is set by the standards specific to this part family, not by ISO 898-1 or ISO 898-2, which apply to bolts, screws and nuts.
