30210-NTN bearing: complete specifications & equivalents
The 30210-NTN is a ISO 355 radial bearing sized 50 x 90 x 21.75 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 50 mm |
| Outer diameter D | 90 mm |
| Width B | 21.75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 85.5 kN |
| Basic static load rating C0 | 93 kN |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 560 g |
| Manufacturer designation | NTN 30210 |
| 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 | 1.969 in |
|---|---|
| Outer diameter D | 3.543 in |
| Width B | 0.856 in |
| ISO bore code | 10 |
| Radial section height (D−d)/2 | 20 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) | 10 of 37 |
| Bore above smallest 30200-series size | 35 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30210 | 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. |
| 30210-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 30210-NTN model number is decoded
NTN supplies this 50 mm bore tapered roller position as 30210: one cone assembly, one cup, line-contact rollers and a steel cage, rated 85.5 kN basic dynamic and 93 kN static on the standard-section 30200 family. Digit by digit, the bare number identifies the standard-section 30200 family and a bore code resolving to 50 mm; 90 mm OD and 21.75 mm assembled T are the matching ISO 355 boundary dimensions shared with other makers of the same dimension series. The printed contact-angle geometry gives the standard-section 30200 family its characteristic load split — at 85.5/93 kN (C/C0) the static rating is about 1.09× C, typical of tapered bearings proportioned for heavy combined duty. The two speed columns differ by a factor of .75 (grease/limiting 4,000 vs oil 5,300 r/min); heat generation at the cone rib decides which lubrication a real 30210 arrangement can sustain. Open 4T bearings need application seals; without them the grease at the cone rib of 30210 washes out and the rib/roller-end contact smears on the first wet or dusty shift.
Typical equipment & failure modes
Common applications
- industrial gearbox and speed-reducer shafts
- bevel and helical pinion drives with high thrust component
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
Known failure patterns
- cone-raceway spalling at the large rib when preload is set too high for the lubricant film
- smearing on the roller large ends and cone rib after a dry start with preload but no oil film
- flaking on one cone only when a back-to-back / face-to-face pair is loaded unevenly by a bent shaft
- cage damage from a mounting blow delivered through the roller complement instead of the ring face
- edge loading when shaft deflection exceeds the few arc-minutes of misalignment the adjusted pair allows
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 50 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 30210.
- The standard-section 30200 family at 50 mm bore (90×21.75 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 5,300 r/min oil ceiling.
- Do not confuse T (21.75 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.
- Minimum load matters at high speed: an unloaded 30210 at a large fraction of 4,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- Minimum load matters at high speed: an unloaded 30210 at a large fraction of 4,000 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 85.5/93 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30210 (ISO 355 3DB); 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 30210?
30210 is a metric 4T tapered roller bearing to ISO 355: 50 mm bore, 90 mm outside diameter and 21.75 mm assembled width T (1.969 × 3.543 × 0.856 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 85.5 kN, C0 93 kN (2203E prints no Pu for this size), grease limiting speed 4,000 r/min, oil speed 5,300 r/min, mass about 560 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30210?
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 (30210); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30210 designation encode the 50 mm bore and what is 3DB?
last two digits 10 are the ISO bore code, ×5 = 50 mm (codes 00–03 use the 10/12/15/17 exception table). The 90 mm OD and 21.75 mm assembled T follow the ISO 355 dimension-series plan. 3DB 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 30210 list two speeds, 4,000 and 5,300 r/min?
The lower figure, 4,000 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30210 at 5,300 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30210 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.