32313U bearing: complete specifications & equivalents
The 32313U is a ISO 355 radial bearing sized 65 x 140 x 51 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 65 mm |
| Outer diameter D | 140 mm |
| Width B | 51 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 305 kN |
| Basic static load rating C0 | 350 kN |
| Fatigue load limit Pu | 42.5 kN |
| Limiting speed (mechanical) | 2800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3630 g |
| Manufacturer designation | NTN 32313U |
| 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 | 2.559 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 2.008 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 37.5 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) | 11 of 30 |
| Bore above smallest 32300-series size | 45 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32313U | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 32313U model number is decoded
32313U belongs to the NTN metric 4T tapered roller range (extra-heavy 32300 family); the open bearing leaves sealing to the application and is normally ordered and mounted as an adjustable matched pair. Digit by digit, the bare number identifies the extra-heavy 32300 family and a bore code resolving to 65 mm; 140 mm OD and 51 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. NTN grades 4T metric bearings as open bearings without integral seals; at 65 mm bore the application supplies the seals and the grease fill or oil supply to the 2GD ISO 355 assembly. Imperial cross-check for the drawing: 65×140×51 mm is 2.559 × 5.512 × 2.008 in; ISO 355 makes the envelope interchangeable but C/C0, 305/350 kN, is NTN-specific. With a rotating shaft a k5/m5 shaft seat and a press-fit cup are typical catalogue practice for 32313U; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- indentation of the raceways by hard particles in unsealed open arrangements
Selection pitfalls — read before you substitute
- Mount the 65 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 3630 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The extra-heavy 32300 family at 65 mm bore (140×51 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 3,700 r/min oil ceiling.
- Never fit the 65 mm cone by hammering the 140 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Minimum load matters at high speed: an unloaded 32313U at a large fraction of 2,800 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 37.5 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32313U or the ring will bottom out on the radius instead of the shoulder face.
- The 305/350 kN ratings and 42.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32313U (ISO 355 2GD); 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 32313U?
32313U is a metric 4T tapered roller bearing to ISO 355: 65 mm bore, 140 mm outside diameter and 51 mm assembled width T (2.559 × 5.512 × 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 305 kN, C0 350 kN, Pu 42.5 kN, grease limiting speed 2,800 r/min, oil speed 3,700 r/min, mass about 3630 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32313U?
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 (32313U); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32313U designation encode the 65 mm bore and what is 2GD?
last two digits 13 are the ISO bore code, ×5 = 65 mm (codes 00–03 use the 10/12/15/17 exception table). The 140 mm OD and 51 mm assembled T follow the ISO 355 dimension-series plan. 2GD 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 32313U list two speeds, 2,800 and 3,700 r/min?
The lower figure, 2,800 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32313U at 3,700 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32313U mean?
Suffix reading on 32313U: 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.