32006X bearing: complete specifications & equivalents
The 32006X is a ISO 355 radial bearing sized 30 x 55 x 17 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 | 55 mm |
| Width B | 17 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 41.5 kN |
| Basic static load rating C0 | 46 kN |
| Limiting speed (mechanical) | 6900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 172 g |
| Manufacturer designation | NTN 32006X |
| 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 & 32000-series range
| Bore d | 1.181 in |
|---|---|
| Outer diameter D | 2.165 in |
| Width B | 0.669 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 12.5 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 650 mm |
| Width range across 32000-series | 15–130 mm |
| Bore position in 32000-series (smallest first) | 5 of 43 |
| Bore above smallest 32000-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32006X | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
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 32006X model number is decoded
In NTN Ball and Roller Bearings CAT.No.2203E, the NTN order number 32006X denotes the low-section 32000 family tuned for low friction of metric tapered roller bearings, 30 mm bore, 55 mm outside diameter and 17 mm assembled width T (1.181 × 2.165 × 0.669 in) to the ISO 355 boundary plan. 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 mm value printed here is T, the width of the fully assembled cone-plus-cup set, not the inner-ring width alone. 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. The 12.5 mm section height over the 30 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 30 mm pair is misadjusted and the 17 mm T set will edge-load in service.
Typical equipment & failure modes
Common applications
- machine-tool gearbox and headstock shafts
- axle final-drive and differential positions
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
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
- cage fatigue when the pair is run continuously near the grease limiting speed without oil cooling
- indentation of the raceways by hard particles in unsealed open arrangements
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 32006X.
- The thin 17 mm section of 32006X is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 30 mm bore smears the roller ends against the rib.
- Never fit the 30 mm cone by hammering the 55 mm cup: force for both press fits goes through the ring faces only, or brinell marks release as noise within the first running hours.
- Open 32006X units have no seals: a wheel-hub or gearbox application needs external sealing or the 6,900 r/min grease figure is meaningless once water reaches the cone rib.
- Replacing one half of an adjusted pair without resetting end play negates the 17 mm T dimension logic: re-adjust the set and re-verify the contact pattern rather than reusing the old spacer stack.
- The 41.5/46 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32006X (ISO 355 4CC); 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 32006X?
32006X is a metric 4T tapered roller bearing to ISO 355: 30 mm bore, 55 mm outside diameter and 17 mm assembled width T (1.181 × 2.165 × 0.669 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 41.5 kN, C0 46 kN (2203E prints no Pu for this size), grease limiting speed 6,900 r/min, oil speed 9,200 r/min, mass about 172 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32006X?
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 (32006X); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32006X designation encode the 30 mm bore and what is 4CC?
last two digits 06 are the ISO bore code, ×5 = 30 mm (codes 00–03 use the 10/12/15/17 exception table). The 55 mm OD and 17 mm assembled T follow the ISO 355 dimension-series plan. 4CC 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 32006X list two speeds, 6,900 and 9,200 r/min?
The lower figure, 6,900 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32006X at 9,200 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32006X mean?
Suffix reading on 32006X: X marks the execution built to the ISO boundary-dimension section (interchangeable envelope, NTN internal geometry); the suffix is part of the order number and the variants are not interchangeable articles.
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.