30210 bearing: complete specifications & equivalents
The 30210 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 |
|---|---|
| Bore diameter d | 50 mm |
| Outer diameter D | 90 mm |
| Width B | 21.75 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) | 488 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 30210 are being backfilled — use the inquiry form for certified values.
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 | 20 mm |
| Largest outer diameter in 30200-series | 200 mm |
| Width range across 30200-series | 15.25–41 mm |
| Bore position in 30200-series (smallest first) | 7 of 19 |
| Bore above smallest 30200-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30210 | 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 30210 model number is decoded
In the 30200-series the last two digits of 30210 encode the bore: code 10 = 50 mm (code × 5 from 04 upward). The ISO 355 envelope is 90 mm outside diameter and 21.75 mm total assembly width T over the separable cone and cup — 1.969 × 3.543 × 0.856 in, with a 20.0 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 50 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
- over-preload heat: a shim stack cut too thin drives contact stress up and seizes the cone on the seat
- 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
Selection pitfalls — read before you substitute
- On this 50 mm-bore 30210, 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 50 mm seat can seize hot.
- The 302 light series at 50 mm bore (90×21.75 mm, 20.0 mm section) is the default general-purpose tapered row; a 32210 on the same 50 mm bore uses the same OD but a wider section for heavier load — it is not a like-for-like width swap.
- Before fitting 30210, machine the 50 mm shaft seat and 90 mm housing bore with a relief or small fillet so nothing bridges the bearing chamfer; the 21.75 mm-wide cone and cup only load correctly when the full faces abut, and a large radius pinches the 20.0 mm radial section.
- The 30210 cup drives into the 90 mm housing bore with a sleeve against its outer face only; pressure on the inner ring or cage transfers through the rollers and leaves indentations that become spalls within the 21.75 mm load zone.
- Inspect the removed 30210 cone and cup as a pair: pitting on the 90 mm cup with a clean cone usually means seal failure and water ingress, while rib scoring on the 50 mm cone points to wrong preload or lost EP film — the two faults need different corrections.
- Set running clearance (or preload) with the shim pack or adjusting nut at fit-up; a 50 mm-bore 30210 that is too tight overheats and scores the rib, one too loose develops end play and noise — follow the torque-and-untighten procedure.
- The sliding contact between roller large ends and the inner-ring rib needs extreme-pressure lubricant; use an EP gear oil or EP grease (GL-5 class in axles) rather than plain bearing grease or the rib will smear in the first heavy run.
Frequently asked questions
What are the dimensions of a 30210 tapered roller bearing?
A 30210 single-row metric tapered roller bearing per ISO 355 has a 50 mm bore, 90 mm outer diameter and 21.75 mm total assembly width (1.969 × 3.543 × 0.856 in), a 20.0 mm radial section and roughly 488 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 30210 bore code work?
The last two digits of 30210 are bore code 10, giving 10 × 5 = 50 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 90 mm OD and 21.75 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 30210?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 30210 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 30210 set?
At fit-up the 50 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 50 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 30210 take axial load in both directions?
A single 30210 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.