30215-NTN bearing: complete specifications & equivalents
The 30215-NTN is a ISO 355 radial bearing sized 75 x 130 x 27.25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 75 mm |
| Outer diameter D | 130 mm |
| Width B | 27.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 154 kN |
| Basic static load rating C0 | 175 kN |
| Limiting speed (mechanical) | 2700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1400 g |
| Manufacturer designation | NTN 30215 |
| 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 & 30200-series range
| Bore d | 2.953 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.073 in |
| ISO bore code | 15 |
| Radial section height (D−d)/2 | 27.5 mm |
| Smallest bore in 30200-series | 15 mm |
| Largest outer diameter in 30200-series | 580 mm |
| Width range across 30200-series | 11.75–104 mm |
| Bore position in 30200-series (smallest first) | 15 of 37 |
| Bore above smallest 30200-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30215 | 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. |
| 30215-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 30215-NTN model number is decoded
30215 is the NTN 4T catalogue entry for a 75×130×27.25 mm metric tapered roller bearing — separable cone and cup, designed for combined radial and axial load as an individually adjusted bearing. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 30215 by the metric ISO 355 number (ISO series abbreviation 4DB): 75 mm bore, 130 mm OD. 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. Grease relubrication at 2,700 r/min limiting speed targets the rib contact; if the drive needs 3,600 r/min it must be arranged for oil lubrication with a defined flow to the large roller ends. Fillet radii must clear the ring chamfers of the 130 mm cup and 75 mm cone; use undercut shoulders so the rings seat fully rather than bridging on a shaft radius.
Typical equipment & failure modes
Common applications
- paper-machine press-section rolls
- large agricultural and forestry machine axles
- heavy industrial gearboxes and crane travel drives
- rolling-mill auxiliary and pinion-stand shafts
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 damage from a mounting blow delivered through the roller complement instead of the ring face
- false brinelling on a stationary paired set exposed to external vibration
Selection pitfalls — read before you substitute
- Mount the 75 mm cone by induction heating (max 120 °C) and the cup with a press sleeve; the 1400 g ring mass makes cocking during fitting a direct raceway-brinelling risk.
- The standard-section 30200 family at 75 mm bore (130×27.25 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 3,600 r/min oil ceiling.
- Replacing one half of an adjusted pair without resetting end play negates the 27.25 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- ISO 355 makes the 75×130 mm envelope interchangeable but not the ratings: NTN prints 154/175 kN for this execution, and a cheaper same-number part can differ in roller complement and steel.
- Replacing one half of an adjusted pair without resetting end play negates the 27.25 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- The 154/175 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30215 (ISO 355 4DB); 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 30215?
30215 is a metric 4T tapered roller bearing to ISO 355: 75 mm bore, 130 mm outside diameter and 27.25 mm assembled width T (2.953 × 5.118 × 1.073 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 154 kN, C0 175 kN (2203E prints no Pu for this size), grease limiting speed 2,700 r/min, oil speed 3,600 r/min, mass about 1400 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30215?
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 (30215); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30215 designation encode the 75 mm bore and what is 4DB?
last two digits 15 are the ISO bore code, ×5 = 75 mm (codes 00–03 use the 10/12/15/17 exception table). The 130 mm OD and 27.25 mm assembled T follow the ISO 355 dimension-series plan. 4DB 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 30215 list two speeds, 2,700 and 3,600 r/min?
The lower figure, 2,700 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30215 at 3,600 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30215 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.