32221-DF bearing: complete specifications & equivalents
The 32221-DF is a ISO 355 radial bearing sized 105 x 190 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 | 105 mm |
| Outer diameter D | 190 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 | 760 kN |
| Basic static load rating C0 | 1020 kN |
| Fatigue load limit Pu | 110 kN |
| Reference speed (thermal) | 2200 rpm |
| Limiting speed (mechanical) | 3400 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 12500 g |
| Manufacturer designation | SKF 32221/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 | 7.48 in |
| Width B | 4.173 in |
| ISO bore code | 21 |
| Radial section height (D−d)/2 | 42.5 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 |
|---|---|---|---|
| 32221 | FAG | 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 32221-DF model number is decoded
Dividing the pair C 760 kN by the 105 mm bore gives 7.24 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. Material and manufacturing detail: the 12500 g catalogue mass reflects through-hardened bearing steel machined to the listed envelope; ring roundness and width tolerance keep the mounted-setting scatter inside the catalogue class. Load sharing in 32221-DF depends on spacer face parallelism; a cocked spacer concentrates the reversing thrust on one bearing of the pair and shows up as asymmetric raceway wear at overhaul. Lubrication for the pair should be sized against the combined 106 mm width and 12500 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, 32221-DF appears as SKF 32221/DF: a matched face-to-face (X) matched pair pair for a 105 mm shaft, rated as a set at C 760 kN and C0 1020 kN.The code breaks down as base bearing 32221 plus matched-set suffix /DF: two bearings of the 105 mm bore size, paired face-to-face (X) matched pair, with the 106 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; 32221-DF therefore runs cooler where the shaft expands axially, at the price of lower moment stiffness than an O-arrangement of the same 105 mm bore.
Typical equipment & failure modes
Common applications
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- heavy industrial gearboxes and speed reducers
Known failure patterns
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- fretting corrosion on a loose rotating shaft seat
- brinelling from pressing the cone or cup home through the rollers
Selection pitfalls — read before you substitute
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 32221-DF concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 32221-DF concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Replace 32221-DF as a complete set: pairing a new bearing with a worn partner leaves the clearance undefined even when the designation matches.
- The 760/1020 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 32221/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 32221-DF?
The SKF 32221/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 105 mm bore, 190 mm outer diameter and 106 mm overall width (4.134 × 7.48 × 4.173 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 760 kN, C0 1020 kN, fatigue load limit Pu 110 kN, reference speed 2,200 r/min, limiting speed 3,400 r/min, mass about 12.50 kg.
What does the /DF suffix on 32221-DF mean?
The base 32221 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 32221-DF for one bearing or the pair?
They are for the complete matched pair: C 760 kN dynamic and C0 1020 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 32221 table values.
Can 32221-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.