32317CU bearing: complete specifications & equivalents
The 32317CU is a ISO 355 radial bearing sized 85 x 180 x 63.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 85 mm |
| Outer diameter D | 180 mm |
| Width B | 63.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 435 kN |
| Basic static load rating C0 | 575 kN |
| Fatigue load limit Pu | 64.5 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7710 g |
| Manufacturer designation | NTN 32317CU |
| 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 | 3.346 in |
|---|---|
| Outer diameter D | 7.087 in |
| Width B | 2.5 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 47.5 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) | 15 of 30 |
| Bore above smallest 32300-series size | 65 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32317CU | 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 32317CU model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 32317CU denotes the extra-heavy 32300 family of metric tapered roller bearings, 85 mm bore, 180 mm outside diameter and 63.5 mm assembled width T (3.346 × 7.087 × 2.5 in) to the ISO 355 boundary plan. Digit by digit, the bare number identifies the extra-heavy 32300 family and a bore code resolving to 85 mm; 180 mm OD and 63.5 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. 2203E lists two speed ceilings for 32317CU: 2,100 r/min with grease lubrication (the limiting speed) and 2,700 r/min with oil, the higher oil value reflecting better heat removal from the cone rib. The fatigue load limit Pu printed for 32317CU is 64.5 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. When pairing 32317CU 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
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
- large conveyor and bucket-elevator pulleys
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- 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 damage from a mounting blow delivered through the roller complement instead of the ring face
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- Mount the 85 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 7710 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The extra-heavy 32300 family at 85 mm bore (180×63.5 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 2,700 r/min oil ceiling.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 85 mm shoulder geometry, because retrofitting flips the cups.
- Never fit the 85 mm cone by hammering the 180 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Grease packs must leave free volume in the 63.5 mm-wide set; over-greasing a paired bearing churning at the 2,700 r/min oil-band speed raises temperature and destroys the preload setting.
- The 435/575 kN ratings and 64.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32317CU (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 32317CU?
32317CU is a metric 4T tapered roller bearing to ISO 355: 85 mm bore, 180 mm outside diameter and 63.5 mm assembled width T (3.346 × 7.087 × 2.5 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 435 kN, C0 575 kN, Pu 64.5 kN, grease limiting speed 2,100 r/min, oil speed 2,700 r/min, mass about 7710 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32317CU?
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 (32317CU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32317CU designation encode the 85 mm bore and what is 5GD?
last two digits 17 are the ISO bore code, ×5 = 85 mm (codes 00–03 use the 10/12/15/17 exception table). The 180 mm OD and 63.5 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 32317CU list two speeds, 2,100 and 2,700 r/min?
The lower figure, 2,100 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32317CU at 2,700 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32317CU mean?
Suffix reading on 32317CU: 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.