32218 bearing: complete specifications & equivalents
The 32218 is a ISO 355 radial bearing sized 90 x 160 x 42.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 90 mm |
| Outer diameter D | 160 mm |
| Width B | 42.5 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) | 2981 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 32218 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 32200-series range
| Bore d | 3.543 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.673 in |
| ISO bore code | 18 |
| Radial section height (D−d)/2 | 35 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) | 15 of 19 |
| Bore above smallest 32200-series size | 70 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32218 | 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 32218 model number is decoded
In the 32200-series the last two digits of 32218 encode the bore: code 18 = 90 mm (code × 5 from 04 upward). The ISO 355 envelope is 160 mm outside diameter and 42.5 mm total assembly width T over the separable cone and cup — 3.543 × 6.299 × 1.673 in, with a 35.0 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 90 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
- 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
- water and grit pitting in unsealed hubs where the cup-cone joint acts as a debris entry path
Selection pitfalls — read before you substitute
- The large 90 mm-bore 32218 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 90 mm shaft.
- The 322 medium series at 90 mm bore (160×42.5 mm) gains roller length and load over the 30218 on the same OD; the wider 42.5 mm assembly needs a wider housing shoulder and changes the pinion offset in a differential.
- The 42.5 mm-wide 32218 ring seats against a shaft and housing shoulder whose fillet must clear the bearing chamfer: keep the corner radius small enough that the 90 mm bore and 160 mm cup seat square — an undercut beats an oversized radius, which lifts the ring and edge-loads the 35.0 mm section.
- When mounting 32218 to a 90 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 160 mm assembly dents the tapered raceway before first run.
- Keep the 32218 pair matched through rebuilds; the 42.5 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 90 mm shaft alignment.
- Tapered rollers accept virtually no misalignment; a deflected 90 mm shaft or a tilted housing shoulder concentrates load on one end of the 42.5 mm-wide roller row — align seats and verify housing perpendicularity.
- Press the 32218 cone onto the 90 mm shaft with force on the inner ring and the cup into the 160 mm housing on the outer ring; driving through the rollers or transmitting mounting force across the assembly brinells the raceways.
Frequently asked questions
What are the dimensions of a 32218 tapered roller bearing?
A 32218 single-row metric tapered roller bearing per ISO 355 has a 90 mm bore, 160 mm outer diameter and 42.5 mm total assembly width (3.543 × 6.299 × 1.673 in), a 35.0 mm radial section and roughly 2981 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32218 bore code work?
The last two digits of 32218 are bore code 18, giving 18 × 5 = 90 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 160 mm OD and 42.5 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32218?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32218 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 32218 set?
At fit-up the 90 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 90 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 32218 take axial load in both directions?
A single 32218 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.