30244-DF bearing: complete specifications & equivalents
The 30244-DF is a ISO 355 radial bearing sized 220 x 400 x 144 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 220 mm |
| Outer diameter D | 400 mm |
| Width B | 144 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1816 kN |
| Basic static load rating C0 | 2800 kN |
| Fatigue load limit Pu | 255 kN |
| Reference speed (thermal) | 950 rpm |
| Limiting speed (mechanical) | 1600 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 72000 g |
| Manufacturer designation | SKF 30244/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 | 8.661 in |
|---|---|
| Outer diameter D | 15.748 in |
| Width B | 5.669 in |
| ISO bore code | 44 |
| Radial section height (D−d)/2 | 90 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) | 28 of 35 |
| Bore above smallest matched-df-series size | 195 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30244 | 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 30244-DF model number is decoded
Reading the designation: 30244 is the ISO 355 single-row base bearing (220 mm bore), and the suffix /DF marks the matched-set execution — arrangement, spacer grinding and factory clearance class. The pair envelope is 220×400×144 mm; the width covers both bearings of the set. Face-to-face matching puts the small rib ends outward, so the pressure cones cross inside the pair; 30244-DF therefore runs cooler where the shaft expands axially, at the price of lower moment stiffness than an O-arrangement of the same 220 mm bore. Catalogue mass 72000 g covers both bearings and the ground spacer of 30244-DF; keep the set complete — substituting one bearing or a non-ground spacer destroys the factory clearance. Material and manufacturing detail: the 72000 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 30244-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. The rotating cones of 30244-DF take a m6 seat on the 220 mm shaft; the cups are a transition-to-loose fit so the pair can be clamped to its factory setting during assembly.The SKF 30244/DF is a 220×400×144 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.
Typical equipment & failure modes
Common applications
- wind-turbine main shafts
- marine propulsion gearboxes
- large industrial mixer shafts
- large industrial mixer shafts
Known failure patterns
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rolling-contact fatigue spalling after the rated L10 life is exceeded
- mounting score marks when the cone is cocked over the shaft keyway or a burr
Selection pitfalls — read before you substitute
- O and X arrangements are not interchangeable by turning the set around: 30244-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 30244-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- A matched /DF set is ground as one system: never separate the two bearings of 30244-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- The 1816/2800 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 30244/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 30244-DF?
The SKF 30244/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 220 mm bore, 400 mm outer diameter and 144 mm overall width (8.661 × 15.748 × 5.669 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1816 kN, C0 2800 kN, fatigue load limit Pu 255 kN, reference speed 950 r/min, limiting speed 1,600 r/min, mass about 72.00 kg.
What does the /DF suffix on 30244-DF mean?
The base 30244 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 30244-DF for one bearing or the pair?
They are for the complete matched pair: C 1816 kN dynamic and C0 2800 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 30244 table values.
Can 30244-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 220 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 220 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.