6580-6535 bearing: complete specifications & equivalents
The 6580-6535 is a ISO 355 radial bearing sized 88.9 x 161.925 x 53.975 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 88.9 mm |
| Outer diameter D | 161.925 mm |
| Width B | 53.975 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 404 kN |
| Basic static load rating C0 | 510 kN |
| Fatigue load limit Pu | 56 kN |
| Reference speed (thermal) | 3200 rpm |
| Limiting speed (mechanical) | 4000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 4800 g |
| Manufacturer designation | SKF 6580/6535 |
| 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 & 6500-series range
| Bore d | 3.5 in |
|---|---|
| Outer diameter D | 6.375 in |
| Width B | 2.125 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 36.5 mm |
| Smallest bore in 6500-series | 88.9 mm |
| Largest outer diameter in 6500-series | 161.925 mm |
| Width range across 6500-series | 53.975–53.975 mm |
| Bore position in 6500-series (smallest first) | 1 of 2 |
| Bore above smallest 6500-series size | 0 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6580-6535-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 88.9×161.925×53.975 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6580-6535 | 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 6580-6535 model number is decoded
For a 88.9 mm shaft the usual cone seat is k5 with an H7 housing when the inner ring rotates; arrange two 6580 bearings as a set for two-direction location and set clearance from the load diagram, never from assembly feel. Load system: the 404 kN basic dynamic rating C and 510 kN static rating C0 give a C0/C balance of 1.26, and dividing C by the 88.9 mm bore yields 4.54 kN per millimetre of journal — a density metric that compares across families; the 56 kN fatigue limit Pu is the floor beneath which the adjusted-life calculation drops below acceptable L10 hours for a 88.9 mm shaft carrying variable duty. Inch tapered bearings are matched sets, not mix-and-match components: 6580 pairs the 6580 cone with the 6535 cup under the 6500-series boundary plan, and although the same cone shows up against other cups in the catalogue, each pairing yields a distinct assembled width and a distinct rating row.SKF 6580 (SKF 6580/6535) is the 6500-series tapered roller choice for a 88.9 mm shaft — one row of tapered rollers on an asymmetric raceway inside the 161.925×53.975 mm envelope.The code breaks down as cone/cup: the numbers before and after the slash identify the inner and outer ring sets, and the series prefix (6500-series) ties the pair to a specific boundary plan. Dimensions 88.9×161.925×53.975 mm are the converted metric envelope. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. Speed planning uses two different ceilings: 3,200 r/min thermal reference and 4,000 r/min mechanical limiting speed.
Typical equipment & failure modes
Common applications
- paper-machine and printing rolls
- construction machinery drives
- marine deck machinery shafts
- construction machinery drives
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
- roller large-end smearing against the cone rib after EP lubricant film failure
- 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
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- Mount the 88.9 mm bore 6580 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The 6500-series inch series at 88.9 mm bore (161.925×53.975 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 6580 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- A single 6580 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- 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 161.925 mm cup race release as noise within the first running hours.
- The 404/510 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 6580 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 6580/6535 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
How does 6580 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 6580 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 6580?
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 53.975 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 6580 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.
What are the dimensions and catalogue data of 6580?
The SKF 6580/6535 is a single-row tapered roller bearing with 88.9 mm bore, 161.925 mm outer diameter and 53.975 mm width (3.5 × 6.375 × 2.125 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 404 kN, C0 510 kN, fatigue load limit Pu 56 kN, reference speed 3,200 r/min, limiting speed 4,000 r/min, mass about 4800 g. It is an open, separable bearing with a pressed-steel cage.
How does the 6580 inch-series designation work?
Inch-series tapered roller bearings use a Timken-style cone/cup convention: the number before the slash identifies the cone (inner ring with roller and cage assembly), the number after the slash identifies the cup (outer ring), and the 6500-series code marks the dimensional series. The metric dimensions 88.9×161.925×53.975 mm are the converted equivalents of the original inch boundary dimensions.
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.