6256-M bearing: complete specifications & equivalents
The 6256-M is a ISO 15 radial bearing sized 280 x 500 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 280 mm |
| Outer diameter D | 500 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 423 kN |
| Basic static load rating C0 | 600 kN |
| Fatigue load limit Pu | 12.9 kN |
| Reference speed (thermal) | 2600 rpm |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 72000 g |
| Manufacturer designation | 6256 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 | 11.024 in |
|---|---|
| Outer diameter D | 19.685 in |
| Width B | 3.15 in |
| ISO bore code | 56 |
| Radial section height (D−d)/2 | 110 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) | 44 of 45 |
| Bore above smallest 6200-series size | 277 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 6256-M model number is decoded
In the 6200-series, the last two digits encode the bore: 6256 carries code 56 = 280 mm (code × 5). The envelope is 280×500×80 mm (11.024×19.685×3.15 in) with a 110.0 mm radial section height, C 423 kN, C0 600 kN and Pu 12.9 kN. The open 6256 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 2200 r/min, catalogue mass 72000 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
- false brinelling from vibration while the shaft stands idle
- fretting corrosion on a creeping shaft or housing seat
Selection pitfalls — read before you substitute
- Catalogue ratings for 6256-M (C 423 kN, C0 600 kN) are SKF figures from PUB BU/P1 17000; geometry revisions can change ratings without changing the designation, so keep the catalogue edition with the specification.
- At 280 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
- The M suffix on 6256-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 72000 g quoted mass includes the heavier cage.
- Open 6256-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 6256-M; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- At 280 mm bore, C3 clearance is the safe choice when interference fits plus temperature rise consume the CN clearance; a hot tight bearing with no residual clearance fails fast.
Frequently asked questions
What are the dimensions of 6256-M?
The SKF 6256 M measures 280 mm bore × 500 mm OD × 80 mm width (11.024 × 19.685 × 3.15 in), mass about 72000 g. It is open, with no shields or seals.
How does the bore code in 6256 work?
The final two digits of 6256 are bore code 56, multiplied by 5 to give 280 mm.
What is the difference between 6256-M and a same-bore 62-series bearing?
Section height differs: 6256-M has a 110 mm radial section and C 423 kN; always match d, D and B — same bore alone never makes two bearings interchangeable.
Which fits should I use for 6256-M?
With a rotating inner ring use roughly m6 on the shaft and H7 in the 500 mm housing; reverse the interference if the outer ring rotates.
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.