23938 bearing: complete specifications & equivalents
The 23938 is a ISO 15 radial bearing sized 190 x 260 x 52 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 190 mm |
| Outer diameter D | 260 mm |
| Width B | 52 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 499 kN |
| Basic static load rating C0 | 800 kN |
| Fatigue load limit Pu | 76.5 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 2600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 8300 g |
| Manufacturer designation | SKF 23938 CC/W33 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings); 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 | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 2.047 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 35 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) | 2 of 17 |
| Bore above smallest 23900-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 23938 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; D/B cross-verified against Schaeffler HR1 2022; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
| 23938-CCK-W33 | SKF | full Dimensions and internal design equivalent — standard interchange. | Tapered-bore (1:12) execution on H3938 adapter sleeve; same ISO 15 envelope, separate order number. |
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 23938 model number is decoded
SKF 23938 (23938 CC/W33) is the spherical-roller choice for a 190 mm shaft — barrel rollers between an inner ring with two raceways and a common sphered outer raceway inside the 260×52 mm ISO 15 envelope. Digit by digit, 23938 reads as bearing type 2 (spherical roller, two barrel-roller rows), dimension series 39, and bore reference 38 resolving to 190 mm; 260 mm OD and 52 mm width are the matching ISO 15 boundary values. The suffix chain reads CC (two pressed-steel cages with a floating guide ring between the roller rows) plus W33 (annular groove and three lubrication holes in the outer ring for relubrication); CCK/W33 is the 1:12 tapered-bore counterpart. The 35.0 mm radial section height ((260−190)/2) and 8300 g catalogue mass frame a 190 mm bore bearing rated at 499 kN C — roughly 2.63 kN of dynamic capacity per millimetre of bore before application factors. Drive-on force must go through the ring being fitted: press or induction-heat the inner ring onto the 190 mm shaft (max 120 °C) and never transmit mounting force through the roller complement, or the raceways brinell.
Typical equipment & failure modes
Common applications
- wind-turbine main shaft support
- heavy rolling-mill work-roll chocks
- large dredger and marine winch drums
- steel-plant continuous-caster segments
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
- cage pocket wear or fracture from roller skew at insufficient minimum load or rapid acceleration
- surface distress and smearing when the relubrication interval is exceeded — the W33 groove is only effective if grease actually reaches the roller rows
- smearing on the roller-raceway contact during skid starts below the minimum load
Selection pitfalls — read before you substitute
- At 190 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 190 mm bore (260×52 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 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 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 499/800 kN ratings are SKF catalogue values for this exact execution (23938 CC/W33); SKF can revise internal geometry without changing the order number, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the specification and re-verify for critical drives.
- SKF lists several executions of 23938 (cylindrical bore as listed, tapered-bore 23938 CCK/W33 variant, plus sealed and vibrating-screen options in the same envelope); they are not interchangeable order numbers — quote the full 23938 CC/W33 designation when purchasing.
Frequently asked questions
What are the dimensions and catalogue data of 23938?
The 23938 CC/W33 is a double-row spherical roller bearing with 190 mm bore, 260 mm outer diameter and 52 mm width (7.48 × 10.236 × 2.047 in) per ISO 15. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 499 kN, C0 800 kN, fatigue load limit Pu 76.5 kN, reference speed 2,400 r/min, limiting speed 2,600 r/min, mass about 8300 g. It is an open, self-aligning bearing with two pressed-steel cages with a floating guide ring.
How does the 23938 bore code work?
The last two digits of 23938 are bore code 38, so 38 × 5 = 190 mm bore. The 260 mm OD and 52 mm width come from the ISO 15 dimension-series plan (dimension series 39 (compact OD, narrow)), shared with other spherical roller bearings of the same code.
What does the CC/W33 suffix mean on 23938?
CC denotes two pressed-steel cages with a floating guide ring between the roller rows, and W33 adds an annular groove plus three lubrication holes in the outer ring for relubrication. CCK/W33 is the 1:12 tapered-bore counterpart.
Can 23938 accommodate misalignment and axial load?
Yes on both counts. The sphered outer raceway lets the bearing self-align ≈ 0.5–2.5° depending on series, absorbing shaft deflection and housing-seat errors. The two barrel-roller rows also carry bidirectional axial load in addition to heavy radial load — this is the key difference from cylindrical roller bearings, which take no axial load.
When should the tapered-bore 23938K variant be used instead?
Choose the K (1:12 tapered bore) variant when the bearing must seat on an adapter or withdrawal sleeve — typical for long shafts, frequent dismounting, or stepped shafts where machining a precision journal is impractical. Sleeve mounting requires measuring clearance reduction or axial drive-up, not nut torque. The cylindrical-bore 23938 listed here seats directly on a machined journal.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings on 2026-09-26. Read our editorial & correction policy.