DIN 127 is the governing dimensional standard for spring lock washers. This page sets out the scope of the standard, reproduces the full size table it specifies, and lists the DIN/ISO/ASME cross-references commonly cited in datasheets and drawings.
DIN 127 — Scope
DIN 127 specifies the dimensions and tolerances of spring lock washers. 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 127, alongside the related ISO 7980 / DIN 127 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 127
| 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.
When to Specify DIN 127
DIN 127 is still widely used in European mechanical engineering and as a cross-reference on legacy drawings; its ISO equivalent is preferred for new designs.