32008 bearing: complete specifications & equivalents
The 32008 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 |
|---|---|
| Bore diameter d | 40 mm |
| Outer diameter D | 68 mm |
| Width B | 19 mm |
| Seal / shield | open |
| Internal clearance | CN available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Operating temperature | -30 to +120 °C |
| Mass (geometry estimate) | 230 g |
| Standard | ISO 355 |
| Catalog version | iso355-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 32008 are being backfilled — use the inquiry form for certified values.
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 | 08 |
| Radial section height (D−d)/2 | 14 mm |
| Smallest bore in 32000-series | 20 mm |
| Largest outer diameter in 32000-series | 225 mm |
| Width range across 32000-series | 15–48 mm |
| Bore position in 32000-series (smallest first) | 5 of 23 |
| Bore above smallest 32000-series size | 20 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32008 | 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 32008 model number is decoded
In the 32000-series the last two digits of 32008 encode the bore: code 08 = 40 mm (code × 5 from 04 upward). The ISO 355 envelope is 68 mm outside diameter and 19 mm total assembly width T over the separable cone and cup — 1.575 × 2.677 × 0.748 in, with a 14.0 mm radial section height. Tapered rollers carry combined radial and single-direction axial load; bidirectional thrust needs an opposed pair (X face-to-face or O back-to-back) adjusted at fit-up. With a rotating cone on a 40 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore, EP lubrication and a defined end-play setting — verify against the load direction and magnitude.
Typical equipment & failure modes
Common applications
- fork-lift steer axles
- industrial transmission shafts
- light-truck and van wheel hubs
- final-drive pinion and differential bearings
- commercial gearbox input/output shafts
Known failure patterns
- under-preload end play that lets the rollers skid, producing noise and false brinelling
- water and grit pitting in unsealed hubs where the cup-cone joint acts as a debris entry path
- false brinelling from vibration while the axle is stationary during transport
- fretting corrosion on a loose shaft seat when the cone is pressed to an interference that relaxes with wear
- cup creep and housing bore fretting when the outer ring is left without its specified press fit
Selection pitfalls — read before you substitute
- On this 40 mm-bore 32008, thermal growth of the shaft closes up the adjusted clearance; set cold end play around 0.03–0.12 mm and recheck after the first hot run — a medium-series cone that was correct cold on the 40 mm seat can seize hot.
- The 320 narrow series at 40 mm bore keeps the OD down to 68 mm for space-limited hubs; its 19 mm width carries less load than a 30208, so do not substitute it into a 302 application without re-rating.
- Check the shoulder geometry for 32008: a generous fillet on the 40 mm shaft looks strong but stops the 19 mm ring seating home; use the catalogue corner-relief radius and provide a withdrawal groove so the 14.0 mm-section cup presses flush in the 68 mm housing.
- Never fit 32008 by tightening the adjuster to force the cone up the 40 mm taper — draw the nut to seat the rollers, then back it off; the 19 mm total width is set by the cup-cone stack, and pushing beyond it is the common cause of seized ribs.
- Relubrication for 32008 must reach the rib-roller end contact, not just the 40 mm bore; in a hub repack, work EP grease through the roller set until it exudes at both faces of the 19 mm-wide assembly or the sliding rib contact starves first.
- The cone and the cup of 32008 are separable: order and fit them as a matched set; never mix a cone from one manufacturer with another brand's cup — roller geometry and contact angle are not identical across brands.
- Set running clearance (or preload) with the shim pack or adjusting nut at fit-up; a 40 mm-bore 32008 that is too tight overheats and scores the rib, one too loose develops end play and noise — follow the torque-and-untighten procedure.
Frequently asked questions
What are the dimensions of a 32008 tapered roller bearing?
A 32008 single-row metric tapered roller bearing per ISO 355 has a 40 mm bore, 68 mm outer diameter and 19 mm total assembly width (1.575 × 2.677 × 0.748 in), a 14.0 mm radial section and roughly 230 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 32008 bore code work?
The last two digits of 32008 are bore code 08, giving 08 × 5 = 40 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 68 mm OD and 19 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 32008?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 32008 denotes a matched cone-and-cup set. They are fitted separately — cone pressed on the shaft, cup in the housing — and adjusted against each other.
How is the preload or clearance of 32008 set?
At fit-up the 40 mm-bore cone is tightened against the cup while the hub is rotated, seated, then backed off to the specified end play — a typical starting range of 0.03–0.12 mm for a 40 mm bore — and locked with shims, a locknut or a spacer. Too tight overheats and seizes the rib; too loose causes skid, noise and early wear. Confirm the exact figure in the hub or axle-maker procedure.
Can 32008 take axial load in both directions?
A single 32008 takes thrust in one direction only — the roller large ends bear against the inner-ring rib under load. Bidirectional axial load requires an opposed pair: X (face-to-face) tolerates misalignment slightly better, O (back-to-back) gives a wider load centre and more moment stiffness.
Reviewed & verified by the MPN Base engineering desk against source catalog iso355-geometry on 2026-09-24. Read our editorial & correction policy.