Specification summary of DIN 6888 as applied to woodruff keys: the dimensions the standard fixes, the full size range supplied, and the related designations commonly cross-referenced.
DIN 6888 — Scope
DIN 6888 specifies the dimensional requirements for woodruff keys. 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 woodruff keys 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 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. 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.

