25580-25523 bearing: complete specifications & equivalents
The 25580-25523 is a ISO 355 radial bearing sized 44.45 x 82.931 x 26.988 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 44.45 mm |
| Outer diameter D | 82.931 mm |
| Width B | 26.988 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 99.1 kN |
| Basic static load rating C0 | 106 kN |
| Fatigue load limit Pu | 11.8 kN |
| Reference speed (thermal) | 6700 rpm |
| Limiting speed (mechanical) | 8000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 610 g |
| Manufacturer designation | SKF 25580/25523 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB |
| Last verified | 2026-09-28 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB) · extracted 2026-09-28
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB); 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 & 25500-series range
| Bore d | 1.75 in |
|---|---|
| Outer diameter D | 3.265 in |
| Width B | 1.063 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 19.2 mm |
| Smallest bore in 25500-series | 38.1 mm |
| Largest outer diameter in 25500-series | 83.058 mm |
| Width range across 25500-series | 23.812–26.988 mm |
| Bore position in 25500-series (smallest first) | 3 of 4 |
| Bore above smallest 25500-series size | 6.350000000000001 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 25580-25520-NTN | NTN | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
| 25580-25523 | Timken | full Dimensions and internal design equivalent — standard interchange. | Same inch-series cone/cup boundary envelope (d/D/T); load ratings and speed limits are brand-specific and may differ. |
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 25580-25523 model number is decoded
The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. ); it is the dimensional series, not a separate part number. At 6,700 r/min reference speed the 19.2 mm-section 25580 is governed thermally by preload and lubricant flow; grease or oil selection should be made against that value, with 8,000 r/min as the mechanical ceiling. Note the minimum-axial-load requirement: at light radial load and high speed the rollers of 25580 must still be held into the rib contact, which is another reason the catalogue recommends paired mounting with controlled setting. Operating context for the 44.45 mm bore: a shaft of this diameter in the medium-bore band typically runs between 35560 and 53340 r/min in real machinery, and the 82.931 mm outside diameter places the housing shoulder at 91 mm outer abutment; the 26.988 mm width and 610 g mass together set the shaft critical speed and the housing resonance check for this 25500-series envelope. Two catalogue entries share the 25580 cone but use different cups; this one, 25580, takes the 25523 cup and is ground for the resulting 82.931 mm OD / 26.988 mm width envelope. Selecting a sibling cup produces a different boundary plan and a different order number, so the full designation is required at purchase.In SKF catalogue PUB BU/P1 17000, 25580 appears as SKF 25580/25523: an open, single-row tapered roller bearing in the 25500-series, supplied with a pressed-steel cage as standard.The 25500-series series assigns 44.45 mm bore, 82.931 mm OD and 26.988 mm width to 25580; the cone and cup references are not interchangeable with other inch-series pairs even when the bore matches, because the cup profile and rib geometry are series-specific.
Typical equipment & failure modes
Common applications
- machine-tool spindles
- belt-driven fan and blower shafts
- axle-boxes in material-handling equipment
- industrial gearbox shafts and reducers
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- false brinelling on idle paired sets exposed to machine vibration
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- mounting score marks when the cone is cocked over the shaft keyway or a burr
Selection pitfalls — read before you substitute
- On this 44.45 mm bore, interference and temperature rise consume clearance inside a preloaded pair; calculate the residual clearance after mounting and at operating temperature — an over-tight 25580 pair heats, loses setting control and smears the roller-rib contact.
- The 25500-series inch series at 44.45 mm bore (82.931×26.988 mm) follows the Timken cone/cup convention; substitutions must match both the cone and cup reference exactly — interchanging with another series or a metric 3xxxx bearing of the same bore changes OD, width and contact angle, so re-run the pair setting and shoulder-diameter checks before swapping.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 25580 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- O (back-to-back) pairs are stiffer against moments, X (face-to-face) pairs tolerate misalignment and thermal growth better; choosing the arrangement from the 2D drawing rather than the actual shaft thermal expansion is a common 25580 mounting error.
- Never press both rings through the wrong element during fitting: force for an interference shaft seat goes through the cone only, or brinell marks on the 82.931 mm cup race release as noise within the first running hours.
- The 99.1/106 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of 25580 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 25580/25523 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What do the cone and cup numbers in 25580 mean?
The cone number (before the slash) identifies the inner ring, rollers and cage; the cup number (after the slash) identifies the outer ring. Both are quoted together because a single-row tapered roller bearing is a matched separable pair — the cone and cup are ground to work together and are not interchangeable with arbitrary other parts. The series prefix (25500-series) groups sizes that share the same boundary-dimension plan.
Can a single 25580 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 25580 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 25580 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 25580?
For a rotating shaft under normal load, seat the cone on a k5 shaft fit; the cup is usually a loose-to-transition fit in the housing so it can creep slightly and distribute wear. Chamfer and shoulder diameters must clear the bearing rings so the 26.988 mm-wide cup seats square; the mounting setting (end play or preload) is set by the axial position of the cup relative to the cone.
Is 25580 interchangeable with other brands?
Inch-series tapered roller bearings follow a long-standing industry boundary plan, so cones and cups of the same basic number are generally dimensionally interchangeable across manufacturers. However, internal geometry, cage design and load ratings differ by brand, so for paired or precision applications keep both halves of the set from one manufacturer — or re-verify ratings and setting when mixing.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.2 inch single-row TRB on 2026-09-28. Read our editorial & correction policy.