32221 bearing: complete specifications & equivalents
The 32221 is a ISO 355 radial bearing sized 105 x 190 x 53 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 105 mm |
| Outer diameter D | 190 mm |
| Width B | 53 mm |
| Seal / shield | open |
| Internal clearance | CN available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 5326 g |
| Standard | ISO 355 |
| Catalog version | iso355-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 32221 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 32200-series range
| Bore d | 4.134 in |
|---|---|
| Outer diameter D | 7.48 in |
| Width B | 2.087 in |
| ISO bore code | 21 |
| Radial section height (D−d)/2 | 42.5 mm |
| Smallest bore in 32200-series | 20 mm |
| Largest outer diameter in 32200-series | 200 mm |
| Width range across 32200-series | 19–56 mm |
| Bore position in 32200-series (smallest first) | 18 of 19 |
| Bore above smallest 32200-series size | 85 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32221 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 32221 model number is decoded
In the 32200-series the last two digits of 32221 encode the bore: code 21 = 105 mm (code × 5 from 04 upward). The ISO 355 envelope is 190 mm outside diameter and 53 mm total assembly width T over the separable cone and cup — 4.134 × 7.48 × 2.087 in, with a 42.5 mm radial section height. Tapered rollers carry combined radial and single-direction axial load; bidirectional thrust needs an opposed pair (X face-to-face or O back-to-back) adjusted at fit-up. With a rotating cone on a 105 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore, EP lubrication and a defined end-play setting — verify against the load direction and magnitude.
Typical equipment & failure modes
Common applications
- heavy final drives and differentials
- large conveyor drum pulleys
- crane travel wheels and winch drums
- railway axle boxes
- agricultural tractor axles
Known failure patterns
- under-preload end play that lets the rollers skid, producing noise and false brinelling
- water and grit pitting in unsealed hubs where the cup-cone joint acts as a debris entry path
- false brinelling from vibration while the axle is stationary during transport
- fretting corrosion on a loose shaft seat when the cone is pressed to an interference that relaxes with wear
- cup creep and housing bore fretting when the outer ring is left without its specified press fit
Selection pitfalls — read before you substitute
- The large 105 mm-bore 32221 develops substantial mounting forces; heat the cone (induction heater, max 120 °C) and never tighten the adjusting nut to seat it — draw it up by torque, then back off to the mark, leaving roughly 0.05–0.20 mm end play on the 105 mm shaft.
- The 322 medium series at 105 mm bore (190×53 mm) gains roller length and load over the 30221 on the same OD; the wider 53 mm assembly needs a wider housing shoulder and changes the pinion offset in a differential.
- The 53 mm-wide 32221 ring seats against a shaft and housing shoulder whose fillet must clear the bearing chamfer: keep the corner radius small enough that the 105 mm bore and 190 mm cup seat square — an undercut beats an oversized radius, which lifts the ring and edge-loads the 42.5 mm section.
- When mounting 32221 to a 105 mm shaft, warm the cone to 80–100 °C and slide it dry to the shoulder; cooling shrinks it into its interference, whereas hammering a cold cone through a 190 mm assembly dents the tapered raceway before first run.
- Keep the 32221 pair matched through rebuilds; the 53 mm running geometry and contact pattern are adjusted between the two cups, so replacing one side with an unmarked row shifts the contact patch off-centre and ruins the 105 mm shaft alignment.
- Assign fits by which ring rotates: an interference shaft fit for a rotating cone; if the cup rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
- A single 32221 takes thrust in ONE direction — the rollers roll toward the rib under load, so reverse thrust unloads the contact. For a wheel or pinion use an opposing 322-series pair adjusted against each other.
Frequently asked questions
What are the dimensions of a 32221 tapered roller bearing?
A 32221 single-row metric tapered roller bearing per ISO 355 has a 105 mm bore, 190 mm outer diameter and 53 mm total assembly width (4.134 × 7.48 × 2.087 in), a 42.5 mm radial section and roughly 5326 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32221 bore code work?
The last two digits of 32221 are bore code 21, giving 21 × 5 = 105 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 190 mm OD and 53 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32221?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32221 denotes a matched cone-and-cup set. They are fitted separately — cone pressed on the shaft, cup in the housing — and adjusted against each other.
How is the preload or clearance of 32221 set?
At fit-up the 105 mm-bore cone is tightened against the cup while the hub is rotated, seated, then backed off to the specified end play — a typical starting range of 0.05–0.20 mm for a 105 mm bore — and locked with shims, a locknut or a spacer. Too tight overheats and seizes the rib; too loose causes skid, noise and early wear. Confirm the exact figure in the hub or axle-maker procedure.
Can 32221 take axial load in both directions?
A single 32221 takes thrust in one direction only — the roller large ends bear against the inner-ring rib under load. Bidirectional axial load requires an opposed pair: X (face-to-face) tolerates misalignment slightly better, O (back-to-back) gives a wider load centre and more moment stiffness.
Reviewed & verified by the MPN Base engineering desk against source catalog iso355-geometry on 2026-09-24. Read our editorial & correction policy.