32964E1 bearing: complete specifications & equivalents
The 32964E1 is a ISO 355 radial bearing sized 320 x 440 x 76 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 320 mm |
| Outer diameter D | 440 mm |
| Width B | 76 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 955 kN |
| Basic static load rating C0 | 1880 kN |
| Fatigue load limit Pu | 153 kN |
| Limiting speed (mechanical) | 670 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 33200 g |
| Manufacturer designation | NTN 32964E1 |
| 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 & 32900-series range
| Bore d | 12.598 in |
|---|---|
| Outer diameter D | 17.323 in |
| Width B | 2.992 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 60 mm |
| Smallest bore in 32900-series | 35 mm |
| Largest outer diameter in 32900-series | 600 mm |
| Width range across 32900-series | 14–100 mm |
| Bore position in 32900-series (smallest first) | 31 of 37 |
| Bore above smallest 32900-series size | 285 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32964E1 | 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 32964E1 model number is decoded
The NTN 2203E table prints 32964E1 in the extra-light thin-section 32900 family: 320 mm bore, 440 mm cup OD, 76 mm T, with a grease limiting speed of 670 r/min and an oil-lubricated ceiling of 900 r/min. Digit by digit, the bare number identifies the extra-light thin-section 32900 family and a bore code resolving to 320 mm; 440 mm OD and 76 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. The pressed-steel cage and surface-finished roller ends are standard 4T execution; ULTAGE-marked variants use upgraded material and internal geometry aimed at longer rating life with the same ISO 355 envelope. Speed planning uses both catalogue columns: grease 670 r/min is the cage/rib mechanical ceiling for 32964E1, oil 900 r/min is available with circulating oil — a 230 r/min margin at this size. With a rotating shaft a m6/n6 shaft seat and a press-fit cup are typical catalogue practice for 32964E1; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- cement-plant kiln and mill drive trains
- rolling-mill roll-neck and gearbox positions
- large crusher and SAG/AG-mill drive shafts
- wind-turbine gearbox and main-shaft arrangements
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- 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
- rolling-contact fatigue after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- At 320 mm bore the 32964E1 set is adjusted with hydraulic nuts on large mill and wind positions; follow the drive-up angle/end-play procedure, because manual torque methods cannot control preload at the 955 kN C level.
- The thin 76 mm section of 32964E1 is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 320 mm bore smears the roller ends against the rib.
- ISO 355 makes the 320×440 mm envelope interchangeable but not the ratings: NTN prints 955/1880 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 320 mm shoulder geometry, because retrofitting flips the cups.
- Replacing one half of an adjusted pair without resetting end play negates the 76 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- The 955/1880 kN ratings and 153 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32964E1; 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 32964E1?
32964E1 is a metric 4T tapered roller bearing to ISO 355: 320 mm bore, 440 mm outside diameter and 76 mm assembled width T (12.598 × 17.323 × 2.992 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 955 kN, C0 1880 kN, Pu 153 kN, grease limiting speed 670 r/min, oil speed 900 r/min, mass about 33200 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32964E1?
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 (32964E1); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32964E1 designation encode the 320 mm bore?
last two digits E1 are the ISO bore code, ×5 = 320 mm (codes 00–03 use the 10/12/15/17 exception table). The 440 mm OD and 76 mm assembled T follow the ISO 355 dimension-series plan.
Why does 32964E1 list two speeds, 670 and 900 r/min?
The lower figure, 670 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32964E1 at 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 32964E1 mean?
It is the basic open 4T execution — steel cage, adjusted mounting, no seal or feature suffix. NTN uses U for the uprated design, UTG for ULTAGE large-bearing specs, X for the ISO boundary section, and C/CA/D/A for contact-angle or internal-design variants; all are separate order numbers.
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.