32040X-DF bearing: complete specifications & equivalents
The 32040X-DF is a ISO 355 radial bearing sized 200 x 310 x 140 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 200 mm |
| Outer diameter D | 310 mm |
| Width B | 140 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1372 kN |
| Basic static load rating C0 | 2750 kN |
| Fatigue load limit Pu | 255 kN |
| Reference speed (thermal) | 1100 rpm |
| Limiting speed (mechanical) | 1900 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 39000 g |
| Manufacturer designation | SKF 32040 X/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 | 7.874 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 5.512 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 55 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) | 27 of 35 |
| Bore above smallest matched-df-series size | 175 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32040X | 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. |
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 32040X-DF model number is decoded
Face-to-face matching puts the small rib ends outward, so the pressure cones cross inside the pair; 32040X-DF therefore runs cooler where the shaft expands axially, at the price of lower moment stiffness than an O-arrangement of the same 200 mm bore. Dividing the pair C 1372 kN by the 200 mm bore gives 6.86 kN per millimetre of journal for the complete arrangement — a density metric that compares matched sets across the face-to-face (X) matched pair family. Journal and housing interface: the 200 mm bore takes a m6 shaft seat and the 310 mm outside diameter pairs with an H7 housing bore; the 140 mm width defines shoulder depth and the 39000 g mass is the dead load in thermal-growth calculations. Spacer discipline: the spacer between the two bearings of 32040X-DF is ground to the individual set — it carries a serial link to the pair, so never swap spacers between sets of the same designation. Do not separate 32040X-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.32040X-DF is a matched pair of single-row tapered roller bearings arranged face-to-face (X) matched pair, supplied by SKF in SKF catalogue PUB BU/P1 17000 as one factory-set unit: the two bearings, spacers and setting are matched together and must not be mixed with other sets.Reading the designation: 32040 X is the ISO 355 single-row base bearing (200 mm bore), and the suffix /DF marks the matched-set execution — arrangement, spacer grinding and factory clearance class. The pair envelope is 200×310×140 mm; the width covers both bearings of the set.
Typical equipment & failure modes
Common applications
- large crusher and mineral-processing drives
- wind-turbine main shafts
- marine propulsion gearboxes
- offshore winch and drawworks drums
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
- electrical pitting on VFD-driven shafts without grounding protection
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- A matched /DF set is ground as one system: never separate the two bearings of 32040X-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- Setting is built into 32040X-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 32040X-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- The 1372/2750 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 32040 X/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 32040X-DF?
The SKF 32040 X/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 200 mm bore, 310 mm outer diameter and 140 mm overall width (7.874 × 12.205 × 5.512 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1372 kN, C0 2750 kN, fatigue load limit Pu 255 kN, reference speed 1,100 r/min, limiting speed 1,900 r/min, mass about 39.00 kg.
What does the /DF suffix on 32040X-DF mean?
The base 32040 X 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 32040X-DF for one bearing or the pair?
They are for the complete matched pair: C 1372 kN dynamic and C0 2750 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 32040 X table values.
Can 32040X-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 200 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 200 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.