8 models in the 81 series, 20.65–20.65 mm bore. Every row links to the full specification page and to the cross-reference page of that model.
| Model | Brand | Bore d (mm) | OD D (mm) | Width B (mm) | |
|---|---|---|---|---|---|
| 8121S | TIMKEN | — | |||
| 8126S | TIMKEN | — | |||
| 8133S | TIMKEN | — | |||
| 8139 | TIMKEN | — | |||
| 8160S | TIMKEN | — | |||
| 8165 | TIMKEN | — | |||
| 8181NA | TIMKEN | — | |||
| 8178 | SKF | 20.65 | — |
81 series bearings follow the ISO dimension plan for this family, so a given number is dimensionally interchangeable between brands - see the cross-reference to confirm. Choose the suffix for your duty: shields for dry, clean positions, contact seals for wet or dusty ones, and a larger clearance class where the fit or temperature demands it.
Other Bearing Accessories series: H · AH · 710 · FIR · 72 · SNW · 73 · C