32021X-DF bearing: complete specifications & equivalents
The 32021X-DF is a ISO 355 radial bearing sized 105 x 160 x 70 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 105 mm |
| Outer diameter D | 160 mm |
| Width B | 70 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 426 kN |
| Basic static load rating C0 | 670 kN |
| Fatigue load limit Pu | 73.5 kN |
| Reference speed (thermal) | 2600 rpm |
| Limiting speed (mechanical) | 3800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 5050 g |
| Manufacturer designation | SKF 32021 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 | 4.134 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 2.756 in |
| ISO bore code | — |
| Radial section height (D−d)/2 | 27.5 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) | 17 of 35 |
| Bore above smallest matched-df-series size | 80 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 32021X | 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 32021X-DF model number is decoded
Catalogue mass 5050 g covers both bearings and the ground spacer of 32021X-DF; keep the set complete — substituting one bearing or a non-ground spacer destroys the factory clearance. Dimensional interchange map: within its boundary plan the 105×160×70 mm envelope of 32021X-DF is fixed, so shoulder, spacer and seal drawings can be dimensioned straight from the catalogue table. Thermal behaviour of the pair: heat generated in the 105 mm bore cones flows along the shaft and changes the setting; the /DF clearance class is chosen for the catalogue speed range 2,600–3,800 r/min, so re-select the clearance class if the application runs hotter. Lubrication for the pair should be sized against the combined 70 mm width and 5050 g mass: two roller sets sweep twice the contact area of a single bearing of the same bore.In SKF catalogue PUB BU/P1 17000, 32021X-DF appears as SKF 32021 X/DF: a matched face-to-face (X) matched pair pair for a 105 mm shaft, rated as a set at C 426 kN and C0 670 kN.Digit by digit, 32021X-DF reads as the ISO 355 base bearing 32021 X supplied as a face-to-face (X) matched pair matched pair (/DF); the 105 mm bore and 160 mm OD are per-bearing, the 70 mm width is for the set. In the face-to-face (X) arrangement the load lines of the two bearings converge toward the shaft axis: the set tolerates shaft deflection and thermal growth better than a back-to-back pair, but is less stiff against overturning moments. The 70 mm overall width of 32021X-DF is the axial space the pair occupies.
Typical equipment & failure modes
Common applications
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- construction machinery drives
Known failure patterns
- false brinelling on idle paired sets exposed to machine vibration
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- fretting corrosion on a loose rotating shaft seat
- hard-particle indentation of the tapered raceway in unfiltered oil
Selection pitfalls — read before you substitute
- Clamp the 32021X-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Clamp the 32021X-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Clamp the 32021X-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- The 426/670 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 32021 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 32021X-DF?
The SKF 32021 X/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 105 mm bore, 160 mm outer diameter and 70 mm overall width (4.134 × 6.299 × 2.756 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 426 kN, C0 670 kN, fatigue load limit Pu 73.5 kN, reference speed 2,600 r/min, limiting speed 3,800 r/min, mass about 5.05 kg.
What does the /DF suffix on 32021X-DF mean?
The base 32021 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 32021X-DF for one bearing or the pair?
They are for the complete matched pair: C 426 kN dynamic and C0 670 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 32021 X table values.
Can 32021X-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 105 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 105 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.