665-653 bearing: complete specifications & equivalents
The 665-653 is a ISO 355 radial bearing sized 85.725 x 146.05 x 41.275 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 85.725 mm |
| Outer diameter D | 146.05 mm |
| Width B | 41.275 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 270 kN |
| Basic static load rating C0 | 320 kN |
| Fatigue load limit Pu | 35.5 kN |
| Reference speed (thermal) | 3600 rpm |
| Limiting speed (mechanical) | 4300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 2650 g |
| Manufacturer designation | SKF 665/653 |
| 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 & 655-series range
| Bore d | 3.375 in |
|---|---|
| Outer diameter D | 5.75 in |
| Width B | 1.625 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 30.2 mm |
| Smallest bore in 655-series | 69.85 mm |
| Largest outer diameter in 655-series | 152.4 mm |
| Width range across 655-series | 41.275–41.275 mm |
| Bore position in 655-series (smallest first) | 3 of 3 |
| Bore above smallest 655-series size | 15.875 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 665-653-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 85.725×146.05×41.275 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 665-653 | 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 665-653 model number is decoded
SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. With C 270 kN and C0 320 kN, the 665 pair-sizing check is dominated by the axial share: keep the equivalent load P below the rating at the required L10, remembering one bearing alone cannot cover reversing thrust at 4,300 r/min. Fit selection follows the rotating ring — interference on a rotating cone — and two 665 units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair. Journal and housing interface: the 85.725 mm bore takes a k5 shaft seat (upper deviation ~0.171 mm for this diameter range) and the 146.05 mm outside diameter pairs with an H7 housing bore tolerance band of 146.05.000/146.070 mm; the 41.275 mm width defines the shoulder depth, and the 2650 g cone-plus-cup assembly is the dead load on the shaft during thermal expansion calculations. Housing and abutment design flows from the cup: in 665 the 653 cup fixes the 146.05 mm OD, the outer-ring face position and the rib shoulder that the rollers contact under thrust, while the 665 cone determines the 85.725 mm shaft interface; the 41.275 mm width is the assembled pair value.665 is a single-row tapered roller bearing in the 655-series inch series: a separable cone-and-cup design for combined radial and one-direction axial load, listed by SKF in SKF catalogue PUB BU/P1 17000.Reading the designation: 665 follows the Timken-style inch convention — the cone (inner ring with rollers) and cup (outer ring) are quoted as a pair separated by a slash, and the 655-series code identifies the dimensional series. The 85.725 mm bore, 146.05 mm OD and 41.275 mm width are the metric equivalents of the inch boundary dimensions.
Typical equipment & failure modes
Common applications
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- 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
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Mount the 85.725 mm bore 665 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 655-series inch series at 85.725 mm bore (146.05×41.275 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.
- Setting is a design value, not an assembly feel: excessive preload in the 665 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 665 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- Catalogue reference speed and limiting speed are different limits: the 3,600 r/min reference is a thermal criterion under load, while the 4,300 r/min limiting value is the mechanical ceiling — observe both.
- The 270/320 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 665 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 665/653 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What do the cone and cup numbers in 665 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 (655-series) groups sizes that share the same boundary-dimension plan.
Can a single 665 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 665 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 665 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
What shaft and housing fits suit 665?
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 41.275 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 665 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.