32020 bearing: complete specifications & equivalents
The 32020 is a ISO 355 radial bearing sized 100 x 150 x 32 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 | 150 mm |
| Width B | 32 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) | 1603 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 32020 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 32000-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 5.906 in |
| Width B | 1.26 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 25 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 225 mm |
| Width range across 32000-series | 15–48 mm |
| Bore position in 32000-series (smallest first) | 17 of 23 |
| Bore above smallest 32000-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32020 | 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 32020 model number is decoded
In the 32000-series the last two digits of 32020 encode the bore: code 20 = 100 mm (code × 5 from 04 upward). The ISO 355 envelope is 150 mm outside diameter and 32 mm total assembly width T over the separable cone and cup — 3.937 × 5.906 × 1.26 in, with a 25.0 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
- railway axle boxes
- agricultural tractor axles
- truck and trailer wheel hubs
- heavy final drives and differentials
- large conveyor drum pulleys
Known failure patterns
- 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
- over-preload heat: a shim stack cut too thin drives contact stress up and seizes the cone on the seat
- under-preload end play that lets the rollers skid, producing noise and false brinelling
Selection pitfalls — read before you substitute
- The large 100 mm-bore 32020 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 320 narrow series at 100 mm bore keeps the OD down to 150 mm for space-limited hubs; its 32 mm width carries less load than a 30220, so do not substitute it into a 302 application without re-rating.
- Check the shoulder geometry for 32020: a generous fillet on the 100 mm shaft looks strong but stops the 32 mm ring seating home; use the catalogue corner-relief radius and provide a withdrawal groove so the 25.0 mm-section cup presses flush in the 150 mm housing.
- Never fit 32020 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 32 mm total width is set by the cup-cone stack, and pushing beyond it is the common cause of seized ribs.
- Relubrication for 32020 must reach the rib-roller end contact, not just the 100 mm bore; in a hub repack, work EP grease through the roller set until it exudes at both faces of the 32 mm-wide assembly or the sliding rib contact starves first.
- Press the 32020 cone onto the 100 mm shaft with force on the inner ring and the cup into the 150 mm housing on the outer ring; driving through the rollers or transmitting mounting force across the assembly brinells the raceways.
- Do not swap a 32000 row for a ball bearing of the same bore: tapered rollers are heavier, slower (sliding rib contact caps the speed) and must be adjusted, but they outperform ball bearings on combined load and shock in gear and hub duty.
Frequently asked questions
What are the dimensions of a 32020 tapered roller bearing?
A 32020 single-row metric tapered roller bearing per ISO 355 has a 100 mm bore, 150 mm outer diameter and 32 mm total assembly width (3.937 × 5.906 × 1.26 in), a 25.0 mm radial section and roughly 1603 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32020 bore code work?
The last two digits of 32020 are bore code 20, giving 20 × 5 = 100 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 150 mm OD and 32 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32020?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32020 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 32020 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 32020 take axial load in both directions?
A single 32020 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.