23988-CCK-W33 bearing: complete specifications & equivalents
The 23988-CCK-W33 is a ISO 15 radial bearing sized 440 x 600 x 118 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 | 600 mm |
| Width B | 118 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 2506 kN |
| Basic static load rating C0 | 4900 kN |
| Fatigue load limit Pu | 345 kN |
| Reference speed (thermal) | 950 rpm |
| Limiting speed (mechanical) | 1000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 150000 g |
| Manufacturer designation | SKF 23988 CCK/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 & 23900-series range
| Bore d | 17.323 in |
|---|---|
| Outer diameter D | 23.622 in |
| Width B | 4.646 in |
| ISO bore code | 88 |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in 23900-series | 180 mm |
| Largest outer diameter in 23900-series | 650 mm |
| Width range across 23900-series | 52–128 mm |
| Bore position in 23900-series (smallest first) | 15 of 17 |
| Bore above smallest 23900-series size | 260 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23988 | SKF | full Dimensions and internal design equivalent — standard interchange. | Tapered-bore (1:12) sleeve-mounted execution of 23988; identical ISO 15 envelope, fits OH3988 adapter sleeve on a 410 mm shaft. |
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 23988-CCK-W33 model number is decoded
In SKF catalogue PUB BU/P1 17000, 23988-cck-w33 denotes the tapered-bore version (K suffix, taper 1:12) of the 23900-series spherical roller bearing: dimensioned 440×600×118 mm, it seats on an adapter or withdrawal sleeve rather than directly on a machined journal. On the SKF nameplate, 23988-cck-w33 follows the ISO 15 convention: 2 for the spherical roller type, 39 for the dimension series 39 (compact OD, narrow), final digits 88 for the 440 mm bore. Sleeve mounting is why the K execution exists: a plain h9-tolerance shaft is enough because the adapter sleeve supplies the precision seat, and the bearing is removable without pulling over an interference journal — a separate order number from the cylindrical-bore bearing, never a field conversion. The 80.0 mm radial section height ((600−440)/2) and 150000 g catalogue mass frame a 440 mm bore bearing rated at 2506 kN C — roughly 5.70 kN of dynamic capacity per millimetre of bore before application factors. After drive-up, re-check radial clearance and then swing the outer ring through its self-aligning range: the sphered raceway of the 23988-cck-w33 must still tilt ≈ 0.5–2.5° freely — a joint that binds after sleeve mounting signals excessive drive-up or a cocked sleeve.
Typical equipment & failure modes
Common applications
- wind-turbine main shaft support
- heavy rolling-mill work-roll chocks
- fan and pulley shafts that need periodic bearing removal in the field
- shafting produced to commercial tolerances, where the adapter sleeve supplies the precision seat
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
- inner-ring circumferential cracking after over-drive on the tapered seat removes too much radial clearance and the bearing runs preloaded
- surface distress and smearing when the relubrication interval is exceeded — the W33 groove is only effective if grease actually reaches the roller rows
- fretting corrosion on a loose rotating shaft seat or in vibratory stand-still
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 23900-series series at 440 mm bore (600×118 mm) is the slim-OD envelope: it buys radial space but gives up capacity against a 222-series bearing of the same bore — confirm the L10 margin before downsizing into it.
- The 23988-cck-w33 and its cylindrical-bore counterpart 23988-cc-w33 share envelope and load ratings (2506/4900 kN) but are not interchangeable in a housing already fitted for direct shaft mounting — the sleeve changes the assembly stack-up.
- The 23988-cck-w33 and its cylindrical-bore counterpart 23988-cc-w33 share envelope and load ratings (2506/4900 kN) but are not interchangeable in a housing already fitted for direct shaft mounting — the sleeve changes the assembly stack-up.
- The 150000 g mass and 118 mm width mean abutment faces must be square to the axis within the bearing's own P0 tolerance; a tilted spacer tilts the outer ring and concentrates load on one roller row of 23988-cck-w33.
- The 2506/4900 kN ratings are SKF catalogue values for this tapered-bore execution (SKF 23988 CCK/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 23988-cck-w33?
The SKF 23988 CCK/W33 is a double-row spherical roller bearing with a 1:12 tapered bore, 440 mm nominal bore, 600 mm outer diameter and 118 mm width (17.323 × 23.622 × 4.646 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: C 2506 kN, C0 4900 kN, Pu 345 kN, reference speed 950 r/min, limiting speed 1,000 r/min, mass about 150000 g. It is mounted on an adapter (H) or withdrawal (AH) sleeve, not directly on the shaft.
What does the K suffix mean on 23988-cck-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 23988-cck-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 23988-cck-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 23988-cck-w33 and 23988-cc-w33?
They share the ISO 15 envelope and the same 2506/4900 kN ratings, but 23988-cck-w33 has the 1:12 tapered bore for sleeve mounting on a plain shaft, while 23988-cc-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.