32938-NTN bearing: complete specifications & equivalents
The 32938-NTN is a ISO 355 radial bearing sized 190 x 260 x 45 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 190 mm |
| Outer diameter D | 260 mm |
| Width B | 45 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 310 kN |
| Basic static load rating C0 | 525 kN |
| Fatigue load limit Pu | 50.5 kN |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 6270 g |
| Manufacturer designation | NTN 32938 |
| 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 | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 1.772 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 35 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) | 24 of 37 |
| Bore above smallest 32900-series size | 155 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32938 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 190×260×45 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 32938-DF | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
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 32938-NTN model number is decoded
NTN supplies this 190 mm bore tapered roller position as 32938: one cone assembly, one cup, line-contact rollers and a steel cage, rated 310 kN basic dynamic and 525 kN static on the extra-light thin-section 32900 family. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation which is the maker-neutral cross-reference for the 190×260 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. 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. The fatigue load limit Pu printed for 32938 is 50.5 kN; in the adjusted-life equation that is the equivalent-load floor below which high reliability is expected even under contamination. With a rotating shaft a m6/n6 shaft seat and a press-fit cup are typical catalogue practice for 32938; reverse the logic if the cup rotates, and re-verify against load direction and magnitude.
Typical equipment & failure modes
Common applications
- large crusher and SAG/AG-mill drive shafts
- wind-turbine gearbox and main-shaft arrangements
- offshore crane and drawworks drums
- heavy haul railway traction gearboxes
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
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- fretting corrosion on a loose cone seat that creeps under rotating load
Selection pitfalls — read before you substitute
- At 190 mm bore the 32938 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 310 kN C level.
- The thin 45 mm section of 32938 is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 190 mm bore smears the roller ends against the rib.
- Never fit the 190 mm cone by hammering the 260 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Replacing one half of an adjusted pair without resetting end play negates the 45 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Replacing one half of an adjusted pair without resetting end play negates the 45 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- The 310/525 kN ratings and 50.5 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32938; 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 32938?
32938 is a metric 4T tapered roller bearing to ISO 355: 190 mm bore, 260 mm outside diameter and 45 mm assembled width T (7.48 × 10.236 × 1.772 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 310 kN, C0 525 kN, Pu 50.5 kN, grease limiting speed 1,200 r/min, oil speed 1,600 r/min, mass about 6270 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32938?
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 (32938); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32938 designation encode the 190 mm bore?
last two digits 38 are the ISO bore code, ×5 = 190 mm (codes 00–03 use the 10/12/15/17 exception table). The 260 mm OD and 45 mm assembled T follow the ISO 355 dimension-series plan.
Why does 32938 list two speeds, 1,200 and 1,600 r/min?
The lower figure, 1,200 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32938 at 1,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32938 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.