23976-CCK-W33 bearing: complete specifications & equivalents
The 23976-CCK-W33 is a ISO 15 radial bearing sized 380 x 520 x 106 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 380 mm |
| Outer diameter D | 520 mm |
| Width B | 106 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 2011 kN |
| Basic static load rating C0 | 3800 kN |
| Fatigue load limit Pu | 285 kN |
| Reference speed (thermal) | 1100 rpm |
| Limiting speed (mechanical) | 1200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 95000 g |
| Manufacturer designation | SKF 23976 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 | 14.961 in |
|---|---|
| Outer diameter D | 20.472 in |
| Width B | 4.173 in |
| ISO bore code | 76 |
| Radial section height (D−d)/2 | 70 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) | 12 of 17 |
| Bore above smallest 23900-series size | 200 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23976 | SKF | full Dimensions and internal design equivalent — standard interchange. | Tapered-bore (1:12) sleeve-mounted execution of 23976; identical ISO 15 envelope, fits OH3976 adapter sleeve on a 360 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 23976-CCK-W33 model number is decoded
For sleeve mounting on a 380 mm shaft, SKF order number SKF 23976 CCK/W33 is the 1:12 tapered-bore spherical roller bearing in the 23900-series family (dimension series 39 (compact OD, narrow)); the cylindrical-bore equivalent is a separate order number, 23976-cc-w33. Numbering ties the bearing to its envelope: 23976-cck-w33 means spherical-roller type, dimension series 39, 380 mm bore — which is why the 520×106 mm outline swaps dimensionally with other ISO 15 bearings of the same code. The K in the designation marks the 1:12 tapered bore: SKF mounts it on an H-series adapter sleeve (with KM locknut and MB lock washer) on a plain commercial-grade shaft, or on an AH withdrawal sleeve where the bearing must abut a shaft shoulder. Speed planning uses two different ceilings: 1,100 r/min thermal reference and 1,200 r/min mechanical limiting speed. After drive-up, re-check radial clearance and then swing the outer ring through its self-aligning range: the sphered raceway of the 23976-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
- large mining crusher main shafts
- wind-turbine main shaft support
- long through-shafts in conveyors, where a sleeve seat avoids a precision journal
- stepped shafts fitted with withdrawal sleeves against a fixed shoulder
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
- surface distress and smearing when the relubrication interval is exceeded — the W33 groove is only effective if grease actually reaches the roller rows
- hard-particle indentation of the raceway in unfiltered oil or contaminated grease systems
Selection pitfalls — read before you substitute
- At 380 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 380 mm bore (520×106 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 adapter sleeve is selected by actual shaft diameter, not by the 380 mm nominal bearing bore: H-sleeve part numbers span a small diameter range, so two different shaft diameters can use the same 23976-cck-w33 with different sleeves.
- The adapter sleeve is selected by actual shaft diameter, not by the 380 mm nominal bearing bore: H-sleeve part numbers span a small diameter range, so two different shaft diameters can use the same 23976-cck-w33 with different sleeves.
- The self-aligning feature is not a license to ignore alignment: beyond ≈ 0.5–2.5° (series-dependent) the edge loading eats the fatigue margin, and seal drag grows as the rings tilt.
- The 2011/3800 kN ratings are SKF catalogue values for this tapered-bore execution (SKF 23976 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 23976-cck-w33?
The SKF 23976 CCK/W33 is a double-row spherical roller bearing with a 1:12 tapered bore, 380 mm nominal bore, 520 mm outer diameter and 106 mm width (14.961 × 20.472 × 4.173 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: C 2011 kN, C0 3800 kN, Pu 285 kN, reference speed 1,100 r/min, limiting speed 1,200 r/min, mass about 95000 g. It is mounted on an adapter (H) or withdrawal (AH) sleeve, not directly on the shaft.
What does the K suffix mean on 23976-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 23976-cck-w33?
The sleeve is selected by the actual shaft diameter in millimetres, not only by the 380 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 23976-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 23976-cck-w33 and 23976-cc-w33?
They share the ISO 15 envelope and the same 2011/3800 kN ratings, but 23976-cck-w33 has the 1:12 tapered bore for sleeve mounting on a plain shaft, while 23976-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.