332-28 bearing: complete specifications & equivalents
The 332-28 is a ISO 355 radial bearing sized 28 x 58 x 24 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 28 mm |
| Outer diameter D | 58 mm |
| Width B | 24 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 64.5 kN |
| Basic static load rating C0 | 69.5 kN |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 293 g |
| Manufacturer designation | NTN 332/28 |
| 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 & 33200-series range
| Bore d | 1.102 in |
|---|---|
| Outer diameter D | 2.283 in |
| Width B | 0.945 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 15 mm |
| Smallest bore in 33200-series | 25 mm |
| Largest outer diameter in 33200-series | 180 mm |
| Width range across 33200-series | 22–63 mm |
| Bore position in 33200-series (smallest first) | 2 of 18 |
| Bore above smallest 33200-series size | 3 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 332 | 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 332-28 model number is decoded
NTN supplies this 28 mm bore tapered roller position as 332/28: one cone assembly, one cup, line-contact rollers and a steel cage, rated 64.5 kN basic dynamic and 69.5 kN static on the medium-wide 33200 family. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 332/28 resolves to 28 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 printed contact-angle geometry gives the medium-wide 33200 family its characteristic load split — at 64.5/69.5 kN (C/C0) the static rating is about 1.08× C, typical of tapered bearings proportioned for heavy combined duty. Grease relubrication at 6,700 r/min limiting speed targets the rib contact; if the drive needs 8,900 r/min it must be arranged for oil lubrication with a defined flow to the large roller ends. Re-adjustment after bedding-in is standard practice: re-check end play once the paired 332/28 arrangement has run in, because initial seat seating relaxes the set preload slightly.
Typical equipment & failure modes
Common applications
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
- industrial gearbox and speed-reducer shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- rolling-contact fatigue after the catalogue L10 life at the actual combined load
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 28 mm bore class are commonly adjusted in pairs; verify end play against the axle drawing and re-torque after bedding-in rather than trusting the initial preload on 332/28.
- The medium-wide 33200 family at 28 mm bore (58×24 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 8,900 r/min oil ceiling.
- Minimum load matters at high speed: an unloaded 332/28 at a large fraction of 6,700 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 15.0 mm section leaves little room for an oversized shaft fillet; check the mounting-chamfer table for 332/28 or the ring will bottom out on the radius instead of the shoulder face.
- Minimum load matters at high speed: an unloaded 332/28 at a large fraction of 6,700 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 64.5/69.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 332/28 (ISO 355 2DE); 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 332/28?
332/28 is a metric 4T tapered roller bearing to ISO 355: 28 mm bore, 58 mm outside diameter and 24 mm assembled width T (1.102 × 2.283 × 0.945 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 64.5 kN, C0 69.5 kN (2203E prints no Pu for this size), grease limiting speed 6,700 r/min, oil speed 8,900 r/min, mass about 293 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 332/28?
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 (332/28); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 332/28 designation encode the 28 mm bore and what is 2DE?
28 mm bore is printed directly after the slash in the slash-size convention. The 58 mm OD and 24 mm assembled T follow the ISO 355 dimension-series plan. 2DE 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 332/28 list two speeds, 6,700 and 8,900 r/min?
The lower figure, 6,700 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 332/28 at 8,900 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 332/28 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.