A4 Stainless Steel (A4-80 (316)) is specified for marine, coastal and chemical applications. When woodruff keys are specified in this grade, the dimensions remain per DIN 6888; the material determines corrosion behavior (superior, including marine and chloride environments) and the service temperature range (approx. -200 °C to +400 °C). Both are covered below with the size table.
Why Choose A4 Stainless Steel for Woodruff Keys
Specified for marine, coastal and chemical applications. For woodruff keys, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| Corrosion characteristic | Superior, including marine and chloride environments |
Galvanic & Galling Considerations
Two important notes for stainless woodruff keys: (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Comparable Grades
For Woodruff Keys, the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Sizes of Woodruff Keys Available in A4 Stainless Steel
| 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 |