32315CU bearing: complete specifications & equivalents
The 32315CU is a ISO 355 radial bearing sized 75 x 160 x 58 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 160 mm |
| Width B | 58 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 365 kN |
| Basic static load rating C0 | 480 kN |
| Fatigue load limit Pu | 56 kN |
| Limiting speed (mechanical) | 2300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 5650 g |
| Manufacturer designation | NTN 32315CU |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 2.283 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 42.5 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) | 13 of 30 |
| Bore above smallest 32300-series size | 55 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32315CU | 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 32315CU model number is decoded
The NTN 2203E table prints 32315CU in the extra-heavy 32300 family: 75 mm bore, 160 mm cup OD, 58 mm T, with a grease limiting speed of 2,300 r/min and an oil-lubricated ceiling of 3,100 r/min. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 32315CU by the metric ISO 355 number (ISO series abbreviation 5GD): 75 mm bore, 160 mm OD. NTN adjusts these bearings by cup or cone position rather than shipping a preloaded set; the mounting drawing must state end play or preload for 32315CU, since running clearance is set during assembly. Catalogue mass of the 32315CU set is 5650 g (0.222 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. When pairing 32315CU with a second tapered bearing, keep the matched arrangement clean: a single stray grit particle between cup and housing changes preload faster than the adjustment range can correct.
Typical equipment & failure modes
Common applications
- rolling-mill auxiliary and pinion-stand shafts
- large conveyor and bucket-elevator pulleys
- mineral-processing feeder and crusher auxiliaries
- marine winch and deck-machinery shafts
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- water-induced pitting when the open bearing is exposed to washdown without external seals
Selection pitfalls — read before you substitute
- Mount the 75 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 5650 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The extra-heavy 32300 family at 75 mm bore (160×58 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 3,100 r/min oil ceiling.
- Minimum load matters at high speed: an unloaded 32315CU at a large fraction of 2,300 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 32315CU by size alone can deliver the wrong contact-angle execution for a pinion position.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 75 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The 365/480 kN ratings and 56 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32315CU (ISO 355 5GD); 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 32315CU?
32315CU is a metric 4T tapered roller bearing to ISO 355: 75 mm bore, 160 mm outside diameter and 58 mm assembled width T (2.953 × 6.299 × 2.283 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 365 kN, C0 480 kN, Pu 56 kN, grease limiting speed 2,300 r/min, oil speed 3,100 r/min, mass about 5650 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32315CU?
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 (32315CU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32315CU designation encode the 75 mm bore and what is 5GD?
last two digits 15 are the ISO bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table). The 160 mm OD and 58 mm assembled T follow the ISO 355 dimension-series plan. 5GD 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 32315CU list two speeds, 2,300 and 3,100 r/min?
The lower figure, 2,300 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32315CU at 3,100 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32315CU mean?
Suffix reading on 32315CU: U marks the reinforced/uprated internal design of the bare number, a separate order number with higher load capacity than the basic execution; the CA/CU/DU letter marks a contact-angle/internal-geometry variant of the same envelope — quote the exact suffix because axial/radial capacity split differs; 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.