6238-M bearing: complete specifications & equivalents
The 6238-M is a ISO 15 radial bearing sized 190 x 340 x 55 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190 mm |
| Outer diameter D | 340 mm |
| Width B | 55 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 255 kN |
| Basic static load rating C0 | 280 kN |
| Fatigue load limit Pu | 7.35 kN |
| Reference speed (thermal) | 3800 rpm |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 21500 g |
| Manufacturer designation | 6238 M |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 6200-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 13.386 in |
| Width B | 2.165 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 75 mm |
| Smallest bore in 6200-series | 3 mm |
| Largest outer diameter in 6200-series | 540 mm |
| Width range across 6200-series | 2.5–85 mm |
| Bore position in 6200-series (smallest first) | 39 of 45 |
| Bore above smallest 6200-series size | 187 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6238-ZZ | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6238ZZ on the same 190×340×55 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| 6238 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6238 (open arrangement) shares the 190×340×55 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
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 6238-M model number is decoded
In the 6200-series, the last two digits encode the bore: 6238 carries code 38 = 190 mm (code × 5). The envelope is 190×340×55 mm (7.48×13.386×2.165 in) with a 75.0 mm radial section height, C 255 kN, C0 280 kN and Pu 7.35 kN. The open 6238 M carries no shields or seals and relies on application lubrication and external sealing. The M suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 3400 r/min, catalogue mass 21500 g.
Typical equipment & failure modes
Common applications
- crusher auxiliary drives
- large industrial gearboxes
- heavy conveyor drives
- hoists and winches
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Deep-groove geometry tolerates only minutes of misalignment; if the 340 mm housing bore cannot be aligned, move to a self-aligning bearing rather than shimming 6238-M.
- Do not preload 6238-M to silence it: a deep-groove ball bearing is not angular-contact, and axial preload only raises temperature and shortens grease life.
- The M suffix on 6238-M denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 21500 g quoted mass includes the heavier cage.
- Open 6238-M needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 6238-M; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Mount by heating the inner ring (max 120 °C) — driving 6238-M home through the outer ring or balls brinells the raceways.
Frequently asked questions
What are the dimensions of 6238-M?
The SKF 6238 M measures 190 mm bore × 340 mm OD × 55 mm width (7.48 × 13.386 × 2.165 in), mass about 21500 g. It is open, with no shields or seals.
How does the bore code in 6238 work?
The final two digits of 6238 are bore code 38, multiplied by 5 to give 190 mm.
Which fits should I use for 6238-M?
With a rotating inner ring use roughly m6 on the shaft and H7 in the 340 mm housing; reverse the interference if the outer ring rotates.
How heavy is 6238-M?
Catalogue mass is 21500 g for 6238 M; seal and cage executions of the same envelope differ by a few grams.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.