30307-NTN bearing: complete specifications & equivalents
The 30307-NTN is a ISO 355 radial bearing sized 35 x 80 x 22.75 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 | 22.75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 83 kN |
| Basic static load rating C0 | 77 kN |
| Limiting speed (mechanical) | 5000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 535 g |
| Manufacturer designation | NTN 30307 |
| 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 & 30300-series range
| Bore d | 1.378 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.896 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 6 of 32 |
| Bore above smallest 30300-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30307 | 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. |
| 30307-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 30307-NTN model number is decoded
The NTN 2203E table prints 30307 in the large-OD 30300 family with the steeper contact angle: 35 mm bore, 80 mm cup OD, 22.75 mm T, with a grease limiting speed of 5,000 r/min and an oil-lubricated ceiling of 6,600 r/min. NTN also quotes this bearing with its ISO 355 dimension-series abbreviation, 2FB, which is the maker-neutral cross-reference for the 35×80 mm envelope; 4T is NTN's own tapered-roller brand mark on the parts. 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 30307, not only the raceway. The 22.5 mm section height over the 35 mm bore positions the load centre; axial location of the pair depends on that contact line, so spacer faces must be square within the P0 tolerance of the bearing. After mounting check the contact pattern with marking blue: a pattern biased to the large or small roller end means the 35 mm pair is misadjusted and the 22.75 mm T set will edge-load in service.
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
- cup creep and housing fretting when the specified outer-ring press fit is not achieved
- 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 damage from a mounting blow delivered through the roller complement instead of the ring face
- fretting corrosion on a loose cone seat that creeps under rotating 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 30307.
- The steeper contact angle of the large-OD 30300 family with the steeper contact angle raises axial capacity but lowers the speed ceiling against a 302/322 bearing at 35 mm bore; do not swap to the lighter family without re-checking the 5,000 r/min grease limit and the thrust load split.
- Never fit the 35 mm cone by hammering the 80 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 35 mm shoulder geometry, because retrofitting flips the cups.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 35 mm shoulder geometry, because retrofitting flips the cups.
- The 83/77 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30307 (ISO 355 2FB); 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 30307?
30307 is a metric 4T tapered roller bearing to ISO 355: 35 mm bore, 80 mm outside diameter and 22.75 mm assembled width T (1.378 × 3.15 × 0.896 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 83 kN, C0 77 kN (2203E prints no Pu for this size), grease limiting speed 5,000 r/min, oil speed 6,600 r/min, mass about 535 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30307?
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 (30307); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30307 designation encode the 35 mm bore and what is 2FB?
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 22.75 mm assembled T follow the ISO 355 dimension-series plan. 2FB 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 30307 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 30307 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 30307 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.