32924-NTN bearing: complete specifications & equivalents
The 32924-NTN is a ISO 355 radial bearing sized 120 x 165 x 29 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 165 mm |
| Width B | 29 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 131 kN |
| Basic static load rating C0 | 205 kN |
| Fatigue load limit Pu | 22.5 kN |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1650 g |
| Manufacturer designation | NTN 32924 |
| 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 | 4.724 in |
|---|---|
| Outer diameter D | 6.496 in |
| Width B | 1.142 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 22.5 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) | 17 of 37 |
| Bore above smallest 32900-series size | 85 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32924 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 120×165×29 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 32924-NTN model number is decoded
NTN supplies this 120 mm bore tapered roller position as 32924: one cone assembly, one cup, line-contact rollers and a steel cage, rated 131 kN basic dynamic and 205 kN static on the extra-light thin-section 32900 family. Digit by digit, the bare number identifies the extra-light thin-section 32900 family and a bore code resolving to 120 mm; 165 mm OD and 29 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. The rollers run with their large ends against the cone's integral guide rib; the rib/end-flange contact carries the thrust component and is the reason lubricant must reach the rib face of 32924, not only the raceway. The 1.1 kN-per-mm-bore capacity figure for 32924 summarises the 131 kN rating over 120 mm bore; use it to sanity-check an interchange candidate before swapping brands. Re-adjustment after bedding-in is standard practice: re-check end play once the paired 32924 arrangement has run in, because initial seat seating relaxes the set preload slightly.
Typical equipment & failure modes
Common applications
- heavy haul railway traction gearboxes
- large marine propulsion reduction gears
- cement-plant kiln and mill drive trains
- rolling-mill roll-neck and gearbox positions
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
- rolling-contact fatigue after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- At 120 mm bore the 32924 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 131 kN C level.
- The thin 29 mm section of 32924 is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 120 mm bore smears the roller ends against the rib.
- Minimum load matters at high speed: an unloaded 32924 at a large fraction of 2,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- Grease packs must leave free volume in the 29 mm-wide set; over-greasing a paired bearing churning at the 2,600 r/min oil-band speed raises temperature and destroys the preload setting.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 120 mm shoulder geometry, because retrofitting flips the cups.
- The 131/205 kN ratings and 22.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32924; 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 32924?
32924 is a metric 4T tapered roller bearing to ISO 355: 120 mm bore, 165 mm outside diameter and 29 mm assembled width T (4.724 × 6.496 × 1.142 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 131 kN, C0 205 kN, Pu 22.5 kN, grease limiting speed 2,000 r/min, oil speed 2,600 r/min, mass about 1650 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32924?
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 (32924); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32924 designation encode the 120 mm bore?
last two digits 24 are the ISO bore code, ×5 = 120 mm (codes 00–03 use the 10/12/15/17 exception table). The 165 mm OD and 29 mm assembled T follow the ISO 355 dimension-series plan.
Why does 32924 list two speeds, 2,000 and 2,600 r/min?
The lower figure, 2,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32924 at 2,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32924 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.