23188-CAK-W33 bearing: complete specifications & equivalents
The 23188-CAK-W33 is a ISO 15 radial bearing sized 440 x 720 x 226 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 440 mm |
| Outer diameter D | 720 mm |
| Width B | 226 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass, machined (M1) |
| Basic dynamic load rating C | 6215 kN |
| Basic static load rating C0 | 10000 kN |
| Fatigue load limit Pu | 670 kN |
| Reference speed (thermal) | 450 rpm |
| Limiting speed (mechanical) | 850 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 430000 g |
| Manufacturer designation | SKF 23188 CAK/W33 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions); 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 & 23100-series range
| Bore d | 17.323 in |
|---|---|
| Outer diameter D | 28.346 in |
| Width B | 8.898 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 140 mm |
| Smallest bore in 23100-series | 100 mm |
| Largest outer diameter in 23100-series | 790 mm |
| Width range across 23100-series | 52–248 mm |
| Bore position in 23100-series (smallest first) | 23 of 25 |
| Bore above smallest 23100-series size | 340 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23188 | SKF | full Dimensions and internal design equivalent — standard interchange. | Tapered-bore (1:12) sleeve-mounted execution of 23188; identical ISO 15 envelope, fits OH3188 adapter sleeve on a 410 mm shaft. |
| C3188-MB | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF CARB toroidal bearing C 3188 MB shares the 440×720×226 mm envelope but catalogue C/C0 differ (6700/11400 kN vs 6215/10000 kN); it floats axially and cannot locate the shaft — pair, never swap one-for-one. |
| C3188-KMB | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF CARB toroidal bearing C 3188 KMB shares the 440×720×226 mm envelope but catalogue C/C0 differ (6700/11400 kN vs 6215/10000 kN); it floats axially and cannot locate the shaft — pair, never swap one-for-one. |
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 23188-CAK-W33 model number is decoded
23188-cak-w33 is the 1:12 tapered-bore execution of the 23100-series spherical roller bearing: the same two barrel-roller rows on a sphered outer raceway as 23188-cak-w33, but the inner-ring bore tapers 1 mm per 12 mm for adapter- or withdrawal-sleeve mounting, as listed by SKF in SKF catalogue PUB BU/P1 17000. Numbering ties the bearing to its envelope: 23188-cak-w33 means spherical-roller type, dimension series 31, 440 mm bore — which is why the 720×226 mm outline swaps dimensionally with other ISO 15 bearings of the same code. Note that K means 1:12 taper; the rarer K30 suffix means 1:30. Adapter sleeves (H) and withdrawal sleeves (AH) are ordered separately by shaft diameter, and the KM locknut plus MB lock washer used for drive-up are also separate components. The 140.0 mm radial section height ((720−440)/2) and 430000 g catalogue mass frame a 440 mm bore bearing rated at 6215 kN C — roughly 14.13 kN of dynamic capacity per millimetre of bore before application factors. Over-driving the 23188-cak-w33 up its sleeve pinches radial clearance below the residual minimum and can crack the inner ring in service; under-driving leaves the sleeve seat loose, so the ring creeps and frets the sleeve — measure, do not estimate.
Typical equipment & failure modes
Common applications
- wind-turbine main shaft support
- heavy rolling-mill work-roll chocks
- heavy crusher and screen shafts mounted and dismounted with hydraulic nuts
- long through-shafts in conveyors, where a sleeve seat avoids a precision journal
Known failure patterns
- raceway fatigue spalling of the sphered outer raceway after extended service above the catalogue L10 rating
- inner-ring raceway spalling from edge loading when misalignment exceeds the self-aligning recovery range
- fretting corrosion and sleeve-seat scoring when drive-up is insufficient and the tapered inner ring creeps on the adapter sleeve
- roller-end scoring from starved lubricant at start-up before the grease channel purges
- seal-lip wear and grease purge loss when an open bearing is run without functioning housing seals
Selection pitfalls — read before you substitute
- At 440 mm bore the ring mass makes cocking during mounting a real risk; guide the bearing square, confirm seat contact around the full circumference, and re-check the self-aligning swing after the housing cap is torqued down.
- The 23100-series series at 440 mm bore (720×226 mm) is the medium-OD wide envelope for heavy continuous duty; it is wider than a 222 bearing in the same OD class, so housing width and spacer stack must be re-checked before substitution.
- The 23188-cak-w33 and its cylindrical-bore counterpart 23188-cak-w33 share envelope and load ratings (6215/10000 kN) but are not interchangeable in a housing already fitted for direct shaft mounting — the sleeve changes the assembly stack-up.
- A loose sleeve after the first weeks of service usually means inadequate initial drive-up; re-checking clearance without dismounting is possible through the 226 mm-wide roller rows with feeler gauges — do not simply tighten the KM nut until vibration stops.
- Open spherical roller bearings rely on the housing seals; in screening or crusher duty a failed seal lets grit into the sphered raceway and the 23188-cak-w33 pits long before its L10 life.
- The 6215/10000 kN ratings are SKF catalogue values for this tapered-bore execution (SKF 23188 CAK/W33); sleeve, KM nut and MB washer are separate order numbers, and the catalogue version (SKF catalogue PUB BU/P1 17000) should travel with the mounting specification.
Frequently asked questions
What are the dimensions and catalogue data of 23188-cak-w33?
The SKF 23188 CAK/W33 is a double-row spherical roller bearing with a 1:12 tapered bore, 440 mm nominal bore, 720 mm outer diameter and 226 mm width (17.323 × 28.346 × 8.898 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: C 6215 kN, C0 10000 kN, Pu 670 kN, reference speed 450 r/min, limiting speed 850 r/min, mass about 430000 g. It is mounted on an adapter (H) or withdrawal (AH) sleeve, not directly on the shaft.
What does the K suffix mean on 23188-cak-w33?
K marks a 1:12 tapered bore for sleeve mounting — SKF writes EK or CCK(/W33), FAG writes -K- inside the suffix chain for sleeve mounting. The bearing seats on an H-series adapter sleeve with a KM locknut and MB lock washer (plain shaft, h9 tolerance), or on an AH withdrawal sleeve against a shaft shoulder. The rarer K30 suffix would instead mean a 1:30 taper; dimension series 40/41 spherical rollers commonly use it.
Which adapter sleeve fits the 23188-cak-w33?
The sleeve is selected by the actual shaft diameter in millimetres, not only by the 440 mm nominal bore: SKF H-sleeve numbers each cover a small shaft-diameter range and are width-series specific (H39/H30/H31/H32 matching dimension series 39/40/31/32), and each kit bundles the sleeve, KM locknut and MB lock washer. For shoulder locations use an AH withdrawal sleeve instead. Confirm the sleeve number against the SKF catalogue PUB BU/P1 17000 mounting tables for your shaft size.
How is the 23188-cak-w33 driven up and checked?
Mounting is controlled by radial-clearance reduction or axial drive-up distance from the SKF catalogue tables for the 1:12 taper, never by locknut torque. Measure clearance with feeler gauges before and after tightening the KM nut, stop at the tabulated decrease, and lock the MB washer tab. Over-drive removes too much clearance (inner-ring cracking risk); under-drive lets the sleeve creep and fret.
What is the difference between 23188-cak-w33 and 23188-cak-w33?
They share the ISO 15 envelope and the same 6215/10000 kN ratings, but 23188-cak-w33 has the 1:12 tapered bore for sleeve mounting on a plain shaft, while 23188-cak-w33 has a cylindrical bore for direct mounting on a machined interference journal (typically m6 with H7 housing). They are separate order numbers, not interchangeable in the same shaft arrangement.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions on 2026-09-26. Read our editorial & correction policy.