32307-NTN bearing: complete specifications & equivalents
The 32307-NTN is a ISO 355 radial bearing sized 35 x 80 x 32.75 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 35 mm |
| Outer diameter D | 80 mm |
| Width B | 32.75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 112 kN |
| Basic static load rating C0 | 115 kN |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 782 g |
| Manufacturer designation | NTN 32307 |
| 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 | 1.378 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 1.289 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 22.5 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) | 5 of 30 |
| Bore above smallest 32300-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32307 | 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 32307-NTN model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 32307 denotes the extra-heavy 32300 family of metric tapered roller bearings, 35 mm bore, 80 mm outside diameter and 32.75 mm assembled width T (1.378 × 3.15 × 1.289 in) to the ISO 355 boundary plan. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 32307 by the metric ISO 355 number (ISO series abbreviation 2FE): 35 mm bore, 80 mm OD. At 112 kN C the bearing offers about 3.2 kN of dynamic capacity per millimetre of the 35 mm bore — compare any substitution on this ratio and the 32.75 mm assembled T, not on bore alone. Catalogue mass of the 32307 set is 782 g (0.031 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. Open 4T bearings need application seals; without them the grease at the cone rib of 32307 washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
- industrial gearbox and speed-reducer shafts
- bevel and helical pinion drives with high thrust component
Known failure patterns
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- rib scoring when axial load is carried beyond the cone rib capacity of the adjusted pair
- preload loss from racewear when one bearing of the paired set is replaced without re-adjusting end play
- 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
- Hub and pinion bearings of this 35 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 32307.
- The extra-heavy 32300 family at 35 mm bore (80×32.75 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 6,600 r/min oil ceiling.
- Replacing one half of an adjusted pair without resetting end play negates the 32.75 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- Do not confuse T (32.75 mm assembled width of cone + cup) with the cone width when drawing spacers; an abutment sized to T instead of the ring width leaves the cup unseated.
- Open 32307 units have no seals: a wheel-hub or gearbox application needs external sealing or the 5,000 r/min grease figure is meaningless once water reaches the cone rib.
- The 112/115 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32307 (ISO 355 2FE); 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 32307?
32307 is a metric 4T tapered roller bearing to ISO 355: 35 mm bore, 80 mm outside diameter and 32.75 mm assembled width T (1.378 × 3.15 × 1.289 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 112 kN, C0 115 kN (2203E prints no Pu for this size), grease limiting speed 5,000 r/min, oil speed 6,600 r/min, mass about 782 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32307?
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 (32307); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32307 designation encode the 35 mm bore and what is 2FE?
last two digits 07 are the ISO bore code, ×5 = 35 mm (codes 00–03 use the 10/12/15/17 exception table). The 80 mm OD and 32.75 mm assembled T follow the ISO 355 dimension-series plan. 2FE 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 32307 list two speeds, 5,000 and 6,600 r/min?
The lower figure, 5,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32307 at 6,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32307 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.