32305-NTN bearing: complete specifications & equivalents
The 32305-NTN is a ISO 355 radial bearing sized 25 x 62 x 25.25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 25 mm |
| Outer diameter D | 62 mm |
| Width B | 25.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 68 kN |
| Basic static load rating C0 | 64.5 kN |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 377 g |
| Manufacturer designation | NTN 32305 |
| 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 | 0.984 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 0.994 in |
| ISO bore code | 05 |
| Radial section height (D−d)/2 | 18.5 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) | 2 of 30 |
| Bore above smallest 32300-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32305 | SKF | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
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 32305-NTN model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 32305 denotes the extra-heavy 32300 family of metric tapered roller bearings, 25 mm bore, 62 mm outside diameter and 25.25 mm assembled width T (0.984 × 2.441 × 0.994 in) to the ISO 355 boundary plan. Reading the designation: the leading five digits follow the ISO 355 metric plan (dimension family plus two-digit bore code), and 32305 resolves to 25 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. With no letter after the number, 32305 is the basic open 4T execution: steel cage, normal adjustment, no seal or special internal-design suffix in the order code. Catalogue mass of the 32305 set is 377 g (0.015 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. When pairing 32305 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
- light-vehicle differential and pinion shafts
- agricultural implement hubs and ground-tool drives
- small gearbox input shafts with combined load
- scooter and light-powersport wheel and gear positions
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
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- At 25 mm bore the thin section and small rollers are adjustment-sensitive: a quarter-turn of the locknut moves end play by more than on large bearings, so set the 32305 pair with a dial indicator rather than by feel.
- The extra-heavy 32300 family at 25 mm bore (62×25.25 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.
- Grease packs must leave free volume in the 25.25 mm-wide set; over-greasing a paired bearing churning at the 8,900 r/min oil-band speed raises temperature and destroys the preload setting.
- On slash-size and T-code bearings confirm the full code on both cone and cup before fitting: the 25 mm bore alone does not identify the cup, and a mismatched cone/cup set has no catalogue rating.
- ISO 355 makes the 25×62 mm envelope interchangeable but not the ratings: NTN prints 68/64.5 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- The 68/64.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32305 (ISO 355 2FD); 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 32305?
32305 is a metric 4T tapered roller bearing to ISO 355: 25 mm bore, 62 mm outside diameter and 25.25 mm assembled width T (0.984 × 2.441 × 0.994 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 68 kN, C0 64.5 kN (2203E prints no Pu for this size), grease limiting speed 6,700 r/min, oil speed 8,900 r/min, mass about 377 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32305?
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 (32305); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32305 designation encode the 25 mm bore and what is 2FD?
last two digits 05 are the ISO bore code, ×5 = 25 mm (codes 00–03 use the 10/12/15/17 exception table). The 62 mm OD and 25.25 mm assembled T follow the ISO 355 dimension-series plan. 2FD 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 32305 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 32305 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 32305 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.