30320-DF bearing: complete specifications & equivalents
The 30320-DF is a ISO 355 radial bearing sized 100 x 215 x 103 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 103 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 739 kN |
| Basic static load rating C0 | 980 kN |
| Fatigue load limit Pu | 106 kN |
| Reference speed (thermal) | 1900 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 17000 g |
| Manufacturer designation | SKF 30320/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 | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 4.055 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 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) | 16 of 35 |
| Bore above smallest matched-df-series size | 75 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30320 | 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 30320-DF model number is decoded
Mounting order matters for 30320-DF: seat the first bearing, fit the ground spacer, then the second bearing, and clamp axially as a unit — the 103 mm catalogue width is the assembled result and the gauge for correct assembly. The rotating cones of 30320-DF take a k5 seat on the 100 mm shaft; the cups are a transition-to-loose fit so the pair can be clamped to its factory setting during assembly.For a 100 mm shaft carrying reversing axial load, SKF lists 30320-DF under catalogue execution SKF 30320/DF: a factory-matched face-to-face (X) matched pair tapered-roller pair, set and measured as one unit.The code breaks down as base bearing 30320 plus matched-set suffix /DF: two bearings of the 100 mm bore size, paired face-to-face (X) matched pair, with the 103 mm overall width spanning the whole arrangement. 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 103 mm overall width of 30320-DF is the axial space the pair occupies. Speed planning for the set uses the catalogue pair values: 1,900 r/min thermal reference and 3,200 r/min mechanical limiting speed — a matched pair runs warmer than one bearing because two roller sets share the 103 mm space. Operating context for the 100 mm bore: a shaft of this diameter typically runs in the large-bore band of industrial duty, and the 215 mm OD places the housing shoulder near 223 mm outer abutment.
Typical equipment & failure modes
Common applications
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
Known failure patterns
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- 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
- mounting score marks when the cone is cocked over the shaft keyway or a burr
- fretting corrosion on a loose rotating shaft seat
Selection pitfalls — read before you substitute
- Clamp the 30320-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 30320-DF concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Setting is built into 30320-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 739/980 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 30320/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 30320-DF?
The SKF 30320/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 100 mm bore, 215 mm outer diameter and 103 mm overall width (3.937 × 8.465 × 4.055 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 739 kN, C0 980 kN, fatigue load limit Pu 106 kN, reference speed 1,900 r/min, limiting speed 3,200 r/min, mass about 17.00 kg.
What does the /DF suffix on 30320-DF mean?
The base 30320 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 30320-DF for one bearing or the pair?
They are for the complete matched pair: C 739 kN dynamic and C0 980 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 30320 table values.
Can 30320-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 (k5 on a rotating 100 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 100 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.