32316CU bearing: complete specifications & equivalents
The 32316CU is a ISO 355 radial bearing sized 80 x 170 x 61.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 80 mm |
| Outer diameter D | 170 mm |
| Width B | 61.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 390 kN |
| Basic static load rating C0 | 505 kN |
| Fatigue load limit Pu | 58 kN |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6610 g |
| Manufacturer designation | NTN 32316CU |
| 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 | 3.15 in |
|---|---|
| Outer diameter D | 6.693 in |
| Width B | 2.421 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 45 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) | 14 of 30 |
| Bore above smallest 32300-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32316CU | 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 32316CU model number is decoded
32316CU 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. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32316CU resolves to 80 mm bore; the NTN factory mark 4T is stamped on cone and cup but is a brand mark, not a size code, so the catalogue sku is printed without it. The 45.0 mm radial section carries the roller complement across the 80–170 mm envelope; section and contact angle differ between NTN metric families even at the same bore, so 302/322/323 are not drop-in swaps. Imperial cross-check for the drawing: 80×170×61.5 mm is 3.15 × 6.693 × 2.421 in; ISO 355 makes the envelope interchangeable but C/C0, 390/505 kN, is NTN-specific. When pairing 32316CU 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
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
- large conveyor and bucket-elevator pulleys
- mineral-processing feeder and crusher auxiliaries
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
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
Selection pitfalls — read before you substitute
- Mount the 80 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 6610 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The extra-heavy 32300 family at 80 mm bore (170×61.5 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 2,900 r/min oil ceiling.
- The 45.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 32316CU or the ring will bottom out on the radius instead of the shoulder face.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 80 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- The U/UTG/X/C/CA/D suffix variants of a base number share the bore but not the article: ordering 32316CU by size alone can deliver the wrong contact-angle execution for a pinion position.
- The 390/505 kN ratings and 58 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32316CU (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 32316CU?
32316CU is a metric 4T tapered roller bearing to ISO 355: 80 mm bore, 170 mm outside diameter and 61.5 mm assembled width T (3.15 × 6.693 × 2.421 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 390 kN, C0 505 kN, Pu 58 kN, grease limiting speed 2,200 r/min, oil speed 2,900 r/min, mass about 6610 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32316CU?
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 (32316CU); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32316CU designation encode the 80 mm bore and what is 5GD?
last two digits 16 are the ISO bore code, ×5 = 80 mm (codes 00–03 use the 10/12/15/17 exception table). The 170 mm OD and 61.5 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 32316CU list two speeds, 2,200 and 2,900 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 32316CU at 2,900 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32316CU mean?
Suffix reading on 32316CU: 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.