30228-DF bearing: complete specifications & equivalents
The 30228-DF is a ISO 355 radial bearing sized 140 x 250 x 91.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 140 mm |
| Outer diameter D | 250 mm |
| Width B | 91.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 773 kN |
| Basic static load rating C0 | 1140 kN |
| Fatigue load limit Pu | 116 kN |
| Reference speed (thermal) | 1500 rpm |
| Limiting speed (mechanical) | 2600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 18000 g |
| Manufacturer designation | SKF 30228/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 | 5.512 in |
|---|---|
| Outer diameter D | 9.843 in |
| Width B | 3.602 in |
| ISO bore code | 28 |
| 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) | 21 of 35 |
| Bore above smallest matched-df-series size | 115 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30228 | 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 30228-DF model number is decoded
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 91.5 mm overall width of 30228-DF is the axial space the pair occupies. With a pair mass of 18000 g across the 140×250×91.5 mm envelope, the set replaces what would otherwise be two separate bearings plus spacer grinding work — the factory setting is the engineering value being purchased. Assembly datum check: verify the 91.5 mm width against the drawing before clamping — the width is the assembled result and the quickest field check that the correct execution of 30228-DF is on the shaft. Inspection shorthand: at overhaul, mark both bearings and the spacer of 30228-DF before disassembly — the set is a matched system, and re-assembling with one component reversed changes the factory setting. A matched /DF set needs no setting adjustment at mounting: the clearance is built in; the assembler's job is clean seats, correct fits (m6 on a 140 mm rotating shaft) and square abutments.The SKF 30228/DF is a 140×250×91.5 mm matched tapered-roller set — two single-row bearings in face-to-face (X) matched pair arrangement, ground and shipped together with the axial clearance fixed at the factory.Numbering ties the set to its envelope: base 30228 fixes the 140 mm bore and 250 mm OD of each bearing, the /DF suffix fixes the arrangement and setting, and the catalogue 91.5 mm width is the combined pair dimension.
Typical equipment & failure modes
Common applications
- wind-turbine main shafts
- marine propulsion gearboxes
- large industrial mixer shafts
- rolling-mill roll-neck bearings
Known failure patterns
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- 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: 30228-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.
- Clamp the 30228-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Setting is built into 30228-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.
- The 773/1140 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 30228/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 30228-DF?
The SKF 30228/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 140 mm bore, 250 mm outer diameter and 91.5 mm overall width (5.512 × 9.843 × 3.602 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 773 kN, C0 1140 kN, fatigue load limit Pu 116 kN, reference speed 1,500 r/min, limiting speed 2,600 r/min, mass about 18.00 kg.
What does the /DF suffix on 30228-DF mean?
The base 30228 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 30228-DF for one bearing or the pair?
They are for the complete matched pair: C 773 kN dynamic and C0 1140 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 30228 table values.
Can 30228-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 140 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 140 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.