32938-DF bearing: complete specifications & equivalents
The 32938-DF is a ISO 355 radial bearing sized 190 x 260 x 90 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 | 90 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 760 kN |
| Basic static load rating C0 | 1530 kN |
| Fatigue load limit Pu | 143 kN |
| Reference speed (thermal) | 1400 rpm |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 14500 g |
| Manufacturer designation | SKF 32938/DF |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants |
| Last verified | 2026-09-29 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants) · extracted 2026-09-29
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants); 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 & matched-df-series range
| Bore d | 7.48 in |
|---|---|
| Outer diameter D | 10.236 in |
| Width B | 3.543 in |
| ISO bore code | 38 |
| Radial section height (D−d)/2 | 35 mm |
| Smallest bore in matched-df-series | 25 mm |
| Largest outer diameter in matched-df-series | 540 mm |
| Width range across matched-df-series | 34.5–280 mm |
| Bore position in matched-df-series (smallest first) | 26 of 35 |
| Bore above smallest matched-df-series size | 165 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32938 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
| 32938-NTN | NTN | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | Model-number interchange per ISO 15; confirm dimensions, sealing and ratings in the supplier catalogue. |
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 32938-DF model number is decoded
Load system: C 760 kN against C0 1530 kN gives a 2.01 balance, and 4.00 kN of dynamic capacity per millimetre of the 190 mm bore is the density figure to compare against neighbouring sizes. Thermal behaviour of the pair: heat generated in the 190 mm bore cones flows along the shaft and changes the setting; the /DF clearance class is chosen for the catalogue speed range 1,400–2,200 r/min, so re-select the clearance class if the application runs hotter. Do not separate 32938-DF into single-bearing service stock — as individual bearings the components are not interchangeable with catalogue single-row executions because the rings are ground for the set.32938-DF (SKF 32938/DF) is the face-to-face (X) matched pair matched-set choice for a 190 mm shaft: a pair of tapered roller bearings whose combined envelope is 260×90 mm, delivered ready to mount with controlled internal clearance.The code breaks down as base bearing 32938 plus matched-set suffix /DF: two bearings of the 190 mm bore size, paired face-to-face (X) matched pair, with the 90 mm overall width spanning the whole arrangement. Face-to-face matching puts the small rib ends outward, so the pressure cones cross inside the pair; 32938-DF therefore runs cooler where the shaft expands axially, at the price of lower moment stiffness than an O-arrangement of the same 190 mm bore. Selection arithmetic: the catalogue C 760 kN and C0 1530 kN are ratings of the complete pair, not of one bearing — never halve them back to a single-row figure when checking L10 life, and use the pair Pu 143 kN as the fatigue floor.
Typical equipment & failure modes
Common applications
- offshore winch and drawworks drums
- rolling-mill roll-neck bearings
- heavy-duty rolling-mill gearboxes
- rolling-mill roll-neck bearings
Known failure patterns
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- roller large-end smearing against the cone rib after EP lubricant film failure
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- brinelling from pressing the cone or cup home through the rollers
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- O and X arrangements are not interchangeable by turning the set around: 32938-DF in face-to-face (X) matched pair arrangement has its load-line geometry fixed — specify the arrangement from the shaft thermal and stiffness analysis.
- Setting is built into 32938-DF; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DF clearance class.
- A matched /DF set is ground as one system: never separate the two bearings of 32938-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- The 760/1530 kN ratings are SKF catalogue 17000 values for this 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.
- Quote the full SKF 32938/DF designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 32938-DF?
The SKF 32938/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 190 mm bore, 260 mm outer diameter and 90 mm overall width (7.48 × 10.236 × 3.543 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 760 kN, C0 1530 kN, fatigue load limit Pu 143 kN, reference speed 1,400 r/min, limiting speed 2,200 r/min, mass about 14.50 kg.
What does the /DF suffix on 32938-DF mean?
The base 32938 is the ISO 355 single-row bearing; the /DF suffix marks the matched-set execution — the arrangement (face-to-face (X)), the ground spacer and the factory-set axial clearance class. A matched set cannot be assembled from loose single bearings; quote the full designation when ordering.
Are the C and C0 ratings of 32938-DF for one bearing or the pair?
They are for the complete matched pair: C 760 kN dynamic and C0 1530 kN static already include load sharing between the two bearings. Do not halve them for single-bearing checks, and do not compare them directly with the single-row 32938 table values.
Can 32938-DF be adjusted like two loose tapered bearings?
No — the axial clearance is set at the factory by selective spacer grinding. Mounting work is limited to clean seats, correct fits (m6 on a rotating 190 mm shaft) and axial clamping through the cones; re-setting in the field destroys the matched clearance class.
When should a face-to-face (X) matched set be chosen?
Choose the face-to-face (X) set where the shaft grows thermally or alignment is imperfect — the converging load lines tolerate deflection. It is the default choice for wheel hubs and general gearbox shafts at the 190 mm bore.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.3-8.8 TRB variants on 2026-09-29. Read our editorial & correction policy.