32312U bearing: complete specifications & equivalents
The 32312U is a ISO 355 radial bearing sized 60 x 130 x 48.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 60 mm |
| Outer diameter D | 130 mm |
| Width B | 48.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 271 kN |
| Basic static load rating C0 | 315 kN |
| Fatigue load limit Pu | 38.5 kN |
| Limiting speed (mechanical) | 3000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3010 g |
| Manufacturer designation | NTN 32312U |
| 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 & 32300-series range
| Bore d | 2.362 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.909 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in 32300-series | 20 mm |
| Largest outer diameter in 32300-series | 460 mm |
| Width range across 32300-series | 22.25–154 mm |
| Bore position in 32300-series (smallest first) | 10 of 30 |
| Bore above smallest 32300-series size | 40 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32312U | 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 32312U model number is decoded
32312U is the NTN 4T catalogue entry for a 60×130×48.5 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. The last two digits 12 are the ISO bore code, ×5 = 60 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 48.5 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. Suffix reading on 32312U: 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. The 4.5 kN-per-mm-bore capacity figure for 32312U summarises the 271 kN rating over 60 mm bore; use it to sanity-check an interchange candidate before swapping brands. Re-adjustment after bedding-in is standard practice: re-check end play once the paired 32312U arrangement has run in, because initial seat seating relaxes the set preload slightly.
Typical equipment & failure modes
Common applications
- marine winch and deck-machinery shafts
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
Selection pitfalls — read before you substitute
- Mount the 60 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 3010 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The extra-heavy 32300 family at 60 mm bore (130×48.5 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 4,000 r/min oil ceiling.
- ISO 355 makes the 60×130 mm envelope interchangeable but not the ratings: NTN prints 271/315 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Grease packs must leave free volume in the 48.5 mm-wide set; over-greasing a paired bearing churning at the 4,000 r/min oil-band speed raises temperature and destroys the preload setting.
- ISO 355 makes the 60×130 mm envelope interchangeable but not the ratings: NTN prints 271/315 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- The 271/315 kN ratings and 38.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32312U (ISO 355 2FD); 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 32312U?
32312U is a metric 4T tapered roller bearing to ISO 355: 60 mm bore, 130 mm outside diameter and 48.5 mm assembled width T (2.362 × 5.118 × 1.909 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 271 kN, C0 315 kN, Pu 38.5 kN, grease limiting speed 3,000 r/min, oil speed 4,000 r/min, mass about 3010 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32312U?
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 (32312U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32312U designation encode the 60 mm bore and what is 2FD?
last two digits 12 are the ISO bore code, ×5 = 60 mm (codes 00–03 use the 10/12/15/17 exception table). The 130 mm OD and 48.5 mm assembled T follow the ISO 355 dimension-series plan. 2FD 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 32312U list two speeds, 3,000 and 4,000 r/min?
The lower figure, 3,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32312U at 4,000 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32312U mean?
Suffix reading on 32312U: 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.