30330-DF bearing: complete specifications & equivalents
The 30330-DF is a ISO 355 radial bearing sized 150 x 320 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 | 150 mm |
| Outer diameter D | 320 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 | 1507 kN |
| Basic static load rating C0 | 2120 kN |
| Fatigue load limit Pu | 208 kN |
| Reference speed (thermal) | 1300 rpm |
| Limiting speed (mechanical) | 2000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 52000 g |
| Manufacturer designation | SKF 30330/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 | 5.906 in |
|---|---|
| Outer diameter D | 12.598 in |
| Width B | 5.669 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 85 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) | 22 of 35 |
| Bore above smallest matched-df-series size | 125 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30330 | 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 30330-DF model number is decoded
30330-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.Digit by digit, 30330-DF reads as the ISO 355 base bearing 30330 supplied as a face-to-face (X) matched pair matched pair (/DF); the 150 mm bore and 320 mm OD are per-bearing, the 144 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 144 mm overall width of 30330-DF is the axial space the pair occupies. Dividing the pair C 1507 kN by the 150 mm bore gives 10.05 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. Cross-section geometry: the 85.0 mm half-section ((320−150)/2) places the roller pitch diameter near 235 mm, and the 144 mm axial width sets the abutment depth — geometry that fixes the contact angle behaviour of 30330-DF. Thermal behaviour of the pair: heat generated in the 150 mm bore cones flows along the shaft and changes the setting; the /DF clearance class is chosen for the catalogue speed range 1,300–2,000 r/min, so re-select the clearance class if the application runs hotter. Clamp the assembled pair axially through the cones — never through the rollers — and verify the 144 mm overall width against the catalogue value before final torquing of the shaft nut.
Typical equipment & failure modes
Common applications
- large industrial mixer shafts
- offshore winch and drawworks drums
- rolling-mill roll-neck bearings
- large industrial mixer shafts
Known failure patterns
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- 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
- brinelling from pressing the cone or cup home through the rollers
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- A matched /DF set is ground as one system: never separate the two bearings of 30330-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- Clamp the 30330-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 30330-DF or swap the spacer — the factory clearance is lost the moment the set is broken.
- The 1507/2120 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 30330/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 30330-DF?
The SKF 30330/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 150 mm bore, 320 mm outer diameter and 144 mm overall width (5.906 × 12.598 × 5.669 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1507 kN, C0 2120 kN, fatigue load limit Pu 208 kN, reference speed 1,300 r/min, limiting speed 2,000 r/min, mass about 52.00 kg.
What does the /DF suffix on 30330-DF mean?
The base 30330 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 30330-DF for one bearing or the pair?
They are for the complete matched pair: C 1507 kN dynamic and C0 2120 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 30330 table values.
Can 30330-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 150 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 150 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.