32320 bearing: complete specifications & equivalents
The 32320 is a ISO 355 radial bearing sized 100 x 215 x 77.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 77.5 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) | 11251 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 32320 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 32300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 3.051 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 mm |
| Smallest bore in 32300-series | 20 mm |
| Largest outer diameter in 32300-series | 240 mm |
| Width range across 32300-series | 22.25–84.5 mm |
| Bore position in 32300-series (smallest first) | 17 of 19 |
| Bore above smallest 32300-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32320 | 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 32320 model number is decoded
In the 32300-series the last two digits of 32320 encode the bore: code 20 = 100 mm (code × 5 from 04 upward). The ISO 355 envelope is 215 mm outside diameter and 77.5 mm total assembly width T over the separable cone and cup — 3.937 × 8.465 × 3.051 in, with a 57.5 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 100 mm shaft, typical catalogue practice is a k5 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
- large conveyor drum pulleys
- crane travel wheels and winch drums
- railway axle boxes
- agricultural tractor axles
- truck and trailer wheel hubs
Known failure patterns
- 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
- roller large-end smearing and scoring against the inner-ring guide rib from loss of the EP lubricant film
- raceway spalling at the roller-rib junction after the L10 life or sustained axial overload
Selection pitfalls — read before you substitute
- The large 100 mm-bore 32320 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 100 mm shaft.
- The 323 heavy wide series at 100 mm bore (215×77.5 mm) is a steep-angle, high-thrust row for heavy final drives; its 57.5 mm section and 77.5 mm width dwarf the 30220, and its speed ceiling is the lowest of the four series.
- Check the shoulder geometry for 32320: a generous fillet on the 100 mm shaft looks strong but stops the 77.5 mm ring seating home; use the catalogue corner-relief radius and provide a withdrawal groove so the 57.5 mm-section cup presses flush in the 215 mm housing.
- Never fit 32320 by tightening the adjuster to force the cone up the 100 mm taper — draw the nut to seat the rollers, then back it off; the 77.5 mm total width is set by the cup-cone stack, and pushing beyond it is the common cause of seized ribs.
- Keep the 32320 pair matched through rebuilds; the 77.5 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 100 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 32320 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 323-series pair adjusted against each other.
Frequently asked questions
What are the dimensions of a 32320 tapered roller bearing?
A 32320 single-row metric tapered roller bearing per ISO 355 has a 100 mm bore, 215 mm outer diameter and 77.5 mm total assembly width (3.937 × 8.465 × 3.051 in), a 57.5 mm radial section and roughly 11251 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32320 bore code work?
The last two digits of 32320 are bore code 20, giving 20 × 5 = 100 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 215 mm OD and 77.5 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32320?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32320 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 32320 set?
At fit-up the 100 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 100 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 32320 take axial load in both directions?
A single 32320 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.