SKF AN21 bearing lock nut (keyway type). Bearing lock nut in the KM series with axial keyway that engages an MB lock washer. Locks a bearing, adapter sleeve or withdrawal sleeve axially on a shaft. Thread size and boundary dimensions per ISO 2982-1 / DIN 981. Nut always paired with the matching MB washer of the same numeric designation.
| Type | Bearing lock nut (keyway type) |
| Designation | SKF AN21 |
| HS code | 8483.30 |
| Thread designation | 4.122-12 |
| Bore diameter | 104.699 mm |
| Outside diameter | 138.252 mm |
| Width | 19.304 mm |
| Locking device | Lock washer |
| Nut for hydraulic mounting | No |
| Associated mounting tool | HN 21-22 |
| Product net weight | 0.8 kg |
| eClass code | 23-11-07-05 |
| UNSPSC code | 31163218 |
| Material | As declared by SKF designation suffix |
| Temperature range | Per SKF product data |
| Primary standard | SKF designation convention (see description for governing ISO / DIN) |
| MOQ | 1 |
Interchange with peer OEM equivalents on identical boundary plan and execution — confirm cage, clearance, sealing and precision-class suffix before substitution.