30206-NTN bearing: complete specifications & equivalents
The 30206-NTN is a ISO 355 radial bearing sized 30 x 62 x 17.25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 30 mm |
| Outer diameter D | 62 mm |
| Width B | 17.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 48.5 kN |
| Basic static load rating C0 | 48 kN |
| Limiting speed (mechanical) | 6300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 236 g |
| Manufacturer designation | NTN 30206 |
| 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 | 1.181 in |
|---|---|
| Outer diameter D | 2.441 in |
| Width B | 0.679 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 16 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) | 6 of 37 |
| Bore above smallest 30200-series size | 15 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30206 | 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. |
| 30206-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 30206-NTN model number is decoded
The NTN 2203E table prints 30206 in the standard-section 30200 family: 30 mm bore, 62 mm cup OD, 17.25 mm T, with a grease limiting speed of 6,300 r/min and an oil-lubricated ceiling of 8,400 r/min. The last two digits 06 are the ISO bore code, ×5 = 30 mm (codes 00–03 use the 10/12/15/17 exception table) under the ISO 355 numbering; the 17.25 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. 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 30206, not only the raceway. Catalogue mass of the 30206 set is 236 g (0.009 lb cone + cup); abutment and shaft shoulder design must carry that mass square to the axis. Mount the 30 mm-bore cone on the shaft first (induction heat, max 120 °C), fit the cup square in its housing, then set preload or end play; never drive the cup home through the rollers of 30206.
Typical equipment & failure modes
Common applications
- pump and compressor drive shafts carrying combined load
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
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 fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- 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 30 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 30206.
- The standard-section 30200 family at 30 mm bore (62×17.25 mm assembled) carries more capacity than the lighter 320/329 sections but generates more preload heat; confirm oil availability before running near the 8,400 r/min oil ceiling.
- Never fit the 30 mm cone by hammering the 62 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Minimum load matters at high speed: an unloaded 30206 at a large fraction of 6,300 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 30 mm shoulder geometry, because retrofitting flips the cups.
- The 48.5/48 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 30206 (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 30206?
30206 is a metric 4T tapered roller bearing to ISO 355: 30 mm bore, 62 mm outside diameter and 17.25 mm assembled width T (1.181 × 2.441 × 0.679 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 48.5 kN, C0 48 kN (2203E prints no Pu for this size), grease limiting speed 6,300 r/min, oil speed 8,400 r/min, mass about 236 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 30206?
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 (30206); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 30206 designation encode the 30 mm bore and what is 3DB?
last two digits 06 are the ISO bore code, ×5 = 30 mm (codes 00–03 use the 10/12/15/17 exception table). The 62 mm OD and 17.25 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 30206 list two speeds, 6,300 and 8,400 r/min?
The lower figure, 6,300 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 30206 at 8,400 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 30206 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.