32008X bearing: complete specifications & equivalents
The 32008X is a ISO 355 radial bearing sized 40 x 68 x 19 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 40 mm |
| Outer diameter D | 68 mm |
| Width B | 19 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 55.5 kN |
| Basic static load rating C0 | 65.5 kN |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 272 g |
| Manufacturer designation | NTN 32008X |
| 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 | 1.575 in |
|---|---|
| Outer diameter D | 2.677 in |
| Width B | 0.748 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 14 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) | 8 of 43 |
| Bore above smallest 32000-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32008X | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
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 32008X model number is decoded
32008X is a metric single-row tapered roller bearing in the NTN 4T programme: a pressed-steel cage guides profiled rollers between a separable cone and cup on the 40×68 mm ISO 355 envelope, with 19 mm overall assembled width T. On the NTN nameplate the parts carry 4T plus the bare code, while 2203E orders 32008X by the metric ISO 355 number (ISO series abbreviation 3CD): 40 mm bore, 68 mm OD. The printed contact-angle geometry gives the low-section 32000 family tuned for low friction its characteristic load split — at 55.5/65.5 kN (C/C0) the static rating is about 1.18× C, typical of tapered bearings proportioned for heavy combined duty. The 1.4 kN-per-mm-bore capacity figure for 32008X summarises the 55.5 kN rating over 40 mm bore; use it to sanity-check an interchange candidate before swapping brands. Mount the 40 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 32008X.
Typical equipment & failure modes
Common applications
- construction-equipment wheel and pivot hubs
- truck and bus wheel hubs in paired arrangements
- industrial gearbox and speed-reducer shafts
- bevel and helical pinion drives with high thrust component
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
- pressed-steel cage pocket wear from roller skid at light radial load and high speed
- brinell marks on cone and cup raceways from impact during handling or hammering during fitting
Selection pitfalls — read before you substitute
- Hub and pinion bearings of this 40 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 32008X.
- The thin 19 mm section of 32008X is built for low friction and tight envelopes, not the heavy preload of a 322/323 set; over-tightening adjustment on this 40 mm bore smears the roller ends against the rib.
- Back-to-back and face-to-face arrangements react differently to shaft bending: pick the pair orientation for the moment load before locking the 40 mm shoulder geometry, because retrofitting flips the cups.
- Never fit the 40 mm cone by hammering the 68 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 32008X at a large fraction of 5,300 r/min lets rollers skid and smear the cone rib; spring-preload lightly loaded pair arrangements.
- The 55.5/65.5 kN ratings here are NTN Ball and Roller Bearings CAT.No.2203E figures for 32008X (ISO 355 3CD); 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 32008X?
32008X is a metric 4T tapered roller bearing to ISO 355: 40 mm bore, 68 mm outside diameter and 19 mm assembled width T (1.575 × 2.677 × 0.748 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 55.5 kN, C0 65.5 kN (2203E prints no Pu for this size), grease limiting speed 5,300 r/min, oil speed 7,100 r/min, mass about 272 g. It is an open, separable cone/cup bearing with a pressed-steel cage.
What does the 4T prefix mean on 32008X?
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 (32008X); the lower-case 4t- factory spelling of the code is retained among the search aliases.
How does the 32008X designation encode the 40 mm bore and what is 3CD?
last two digits 08 are the ISO bore code, ×5 = 40 mm (codes 00–03 use the 10/12/15/17 exception table). The 68 mm OD and 19 mm assembled T follow the ISO 355 dimension-series plan. 3CD 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 32008X list two speeds, 5,300 and 7,100 r/min?
The lower figure, 5,300 r/min, is the grease-lubricated limiting speed — the mechanical ceiling for the cage, rollers and cone-rib contact. With oil lubrication NTN rates 32008X at 7,100 r/min because oil removes rib-contact heat better. Real limits still depend on preload, oil flow and cooling.
What does the suffix on 32008X mean?
Suffix reading on 32008X: 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.