DIN 6888 covers the dimensional requirements for woodruff keys. Reproduced below: the complete size table, the tolerance grades, and the companion and equivalent standards referenced when ordering to this document.
DIN 6888 — Scope
DIN 6888 specifies the dimensions and tolerances of woodruff keys. 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 6888, alongside the related DIN 6888 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 6888
| Key width b (mm) | Disc diameter d (mm) | Key height h (mm) | Chord length l (mm) | Shaft groove depth t1 (mm) | Hub groove depth t2 (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 1.0 | 4 | 1.4 | 3.7 | 1.0 | 0.6 | DIN 6888 / ISO 3912 |
| 1.5 | 4 | 1.4 | 3.7 | 1.0 | 0.6 | DIN 6888 / ISO 3912 |
| 2.0 | 5 | 1.8 | 4.7 | 1.4 | 0.6 | DIN 6888 / ISO 3912 |
| 2.0 | 6 | 2.6 | 5.7 | 2.0 | 0.8 | DIN 6888 / ISO 3912 |
| 2.5 | 7 | 3.0 | 6.8 | 2.3 | 1.0 | DIN 6888 / ISO 3912 |
| 3.0 | 7 | 3.0 | 6.8 | 2.3 | 1.0 | DIN 6888 / ISO 3912 |
| 3.0 | 9 | 4.0 | 8.8 | 3.2 | 1.0 | DIN 6888 / ISO 3912 |
| 3.0 | 10 | 4.5 | 9.8 | 3.5 | 1.2 | DIN 6888 / ISO 3912 |
| 4.0 | 9 | 4.0 | 8.8 | 3.2 | 1.0 | DIN 6888 / ISO 3912 |
| 4.0 | 10 | 4.5 | 9.8 | 3.5 | 1.2 | DIN 6888 / ISO 3912 |
| 4.0 | 13 | 6.0 | 12.7 | 5.0 | 1.4 | DIN 6888 / ISO 3912 |
| 5.0 | 10 | 4.5 | 9.8 | 3.5 | 1.2 | DIN 6888 / ISO 3912 |
| 5.0 | 13 | 6.0 | 12.7 | 5.0 | 1.4 | DIN 6888 / ISO 3912 |
| 5.0 | 16 | 7.5 | 15.7 | 6.3 | 1.4 | DIN 6888 / ISO 3912 |
| 6.0 | 13 | 6.0 | 12.7 | 5.0 | 1.4 | DIN 6888 / ISO 3912 |
| 6.0 | 16 | 7.5 | 15.7 | 6.3 | 1.4 | DIN 6888 / ISO 3912 |
| 6.0 | 19 | 9.0 | 18.6 | 7.5 | 1.8 | DIN 6888 / ISO 3912 |
| 8.0 | 19 | 9.0 | 18.6 | 7.5 | 1.8 | DIN 6888 / ISO 3912 |
| 8.0 | 22 | 11.0 | 21.6 | 9.3 | 1.8 | DIN 6888 / ISO 3912 |
| 10.0 | 22 | 11.0 | 21.6 | 9.3 | 1.8 | DIN 6888 / ISO 3912 |
| 10.0 | 25 | 13.0 | 24.5 | 11.0 | 2.3 | DIN 6888 / ISO 3912 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Woodruff Keys page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
DIN 6888 controls only the geometry of woodruff keys. 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).