30206 bearing: complete specifications & equivalents
The 30206 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 |
|---|---|
| Bore diameter d | 30 mm |
| Outer diameter D | 62 mm |
| Width B | 17.25 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) | 204 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 30206 are being backfilled — use the inquiry form for certified values.
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 | 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) | 3 of 19 |
| Bore above smallest 30200-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30206 | 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 30206 model number is decoded
In the 30200-series the last two digits of 30206 encode the bore: code 06 = 30 mm (code × 5 from 04 upward). The ISO 355 envelope is 62 mm outside diameter and 17.25 mm total assembly width T over the separable cone and cup — 1.181 × 2.441 × 0.679 in, with a 16.0 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 30 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
- passenger-car wheel hubs
- small trailer axles
- light differential pinions
- steering knuckles
- small gearbox shafts
Known failure patterns
- 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
- roller large-end smearing and scoring against the inner-ring guide rib from loss of the EP lubricant film
- raceway spalling at the roller-rib junction after the L10 life or sustained axial overload
- over-preload heat: a shim stack cut too thin drives contact stress up and seizes the cone on the seat
Selection pitfalls — read before you substitute
- At 30 mm bore the small 30206 is commonly factory-adjusted in a hub unit; an after-market fit-up must reproduce the specified end play (a typical starting range of 0.02–0.10 mm at the 30 mm shaft) or the wheel runs hot within the first hundred kilometres.
- The 302 light series at 30 mm bore (62×17.25 mm, 16.0 mm section) is the default general-purpose tapered row; a 32206 on the same 30 mm bore uses the same OD but a wider section for heavier load — it is not a like-for-like width swap.
- The 17.25 mm-wide 30206 ring seats against a shaft and housing shoulder whose fillet must clear the bearing chamfer: keep the corner radius small enough that the 30 mm bore and 62 mm cup seat square — an undercut beats an oversized radius, which lifts the ring and edge-loads the 16.0 mm section.
- When mounting 30206 to a 30 mm shaft, warm the cone to 80–100 °C and slide it dry to the shoulder; cooling shrinks it into its interference, whereas hammering a cold cone through a 62 mm assembly dents the tapered raceway before first run.
- Relubrication for 30206 must reach the rib-roller end contact, not just the 30 mm bore; in a hub repack, work EP grease through the roller set until it exudes at both faces of the 17.25 mm-wide assembly or the sliding rib contact starves first.
- Do not swap a 30200 row for a ball bearing of the same bore: tapered rollers are heavier, slower (sliding rib contact caps the speed) and must be adjusted, but they outperform ball bearings on combined load and shock in gear and hub duty.
- Assign fits by which ring rotates: an interference shaft fit for a rotating cone; if the cup rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
Frequently asked questions
What are the dimensions of a 30206 tapered roller bearing?
A 30206 single-row metric tapered roller bearing per ISO 355 has a 30 mm bore, 62 mm outer diameter and 17.25 mm total assembly width (1.181 × 2.441 × 0.679 in), a 16.0 mm radial section and roughly 204 g geometry-based estimated mass; catalogue masses vary with roller and cage design.
How does the 30206 bore code work?
The last two digits of 30206 are bore code 06, giving 06 × 5 = 30 mm bore — the same convention as 6xx ball bearings, starting at code 04 (20 mm). The 62 mm OD and 17.25 mm width come from the ISO 355 diameter and width series, not the bore code alone.
What is the cone and cup of 30206?
Tapered roller bearings are separable: the cone is the inner ring with the tapered rollers and cage, the cup is the outer ring. 30206 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 30206 set?
At fit-up the 30 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 0.02–0.10 mm for a 30 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 30206 take axial load in both directions?
A single 30206 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.