32218U bearing: complete specifications & equivalents
The 32218U 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 |
|---|---|
| Brand | NTN |
| Bore diameter d | 90 mm |
| Outer diameter D | 160 mm |
| Width B | 42.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 291 kN |
| Basic static load rating C0 | 360 kN |
| Fatigue load limit Pu | 41 kN |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3490 g |
| Manufacturer designation | NTN 32218U |
| Standard | ISO 355 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
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 | — |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 32200-series | 17 mm |
| Largest outer diameter in 32200-series | 580 mm |
| Width range across 32200-series | 17.25–159 mm |
| Bore position in 32200-series (smallest first) | 17 of 36 |
| Bore above smallest 32200-series size | 73 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32218U | 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 32218U model number is decoded
NTN supplies this 90 mm bore tapered roller position as 32218U: one cone assembly, one cup, line-contact rollers and a steel cage, rated 291 kN basic dynamic and 360 kN static on the heavy-section 32200 family. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 32218U by the metric ISO 355 number (ISO series abbreviation 3FC): 90 mm bore, 160 mm OD. At 291 kN C the bearing offers about 3.2 kN of dynamic capacity per millimetre of the 90 mm bore — compare any substitution on this ratio and the 42.5 mm assembled T, not on bore alone. Selection: C 291 kN against C0 360 kN gives a C0/C ratio of 1.24 for the 90 mm bore, and the equivalent combined load must keep below the rating at the target L10 with the pair counted as one unit. Fillet radii must clear the ring chamfers of the 160 mm cup and 90 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- mineral-processing feeder and crusher auxiliaries
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
- large agricultural and forestry machine axles
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- indentation of the raceways by hard particles in unsealed open arrangements
Selection pitfalls — read before you substitute
- Mount the 90 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 3490 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The heavy-section 32200 family at 90 mm bore (160×42.5 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 3,000 r/min oil ceiling.
- The 35.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32218U or the ring will bottom out on the radius instead of the shoulder face.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 90 mm shoulder geometry, because retrofitting flips the cups.
- Open 32218U units have no seals: a wheel-hub or gearbox application needs external sealing or the 2,200 r/min grease figure is meaningless once water reaches the cone rib.
- The 291/360 kN ratings and 41 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32218U (ISO 355 3FC); internal geometry legitimately differs between manufacturers, so re-verify ratings, adjustment and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 32218U?
32218U is a metric 4T tapered roller bearing to ISO 355: 90 mm bore, 160 mm outside diameter and 42.5 mm assembled width T (3.543 × 6.299 × 1.673 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 291 kN, C0 360 kN, Pu 41 kN, grease limiting speed 2,200 r/min, oil speed 3,000 r/min, mass about 3490 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32218U?
4T is NTN's tapered roller bearing brand mark, stamped on the cone and cup in the factory. It identifies the NTN 4T programme and is not a dimension, so the catalogue and this page list the bare ISO 355 number (32218U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32218U designation encode the 90 mm bore and what is 3FC?
last two digits 18 are the ISO bore code, ×5 = 90 mm (codes 00–03 use the 10/12/15/17 exception table). The 160 mm OD and 42.5 mm assembled T follow the ISO 355 dimension-series plan. 3FC is the maker-neutral ISO 355 abbreviation for this dimension series (the same code other manufacturers print); 4T is NTN's own brand mark.
Why does 32218U list two speeds, 2,200 and 3,000 r/min?
The lower figure, 2,200 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32218U at 3,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32218U mean?
Suffix reading on 32218U: U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; the suffix is part of the order number and the variants are not interchangeable articles.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.