30211-DF bearing: complete specifications & equivalents
The 30211-DF is a ISO 355 radial bearing sized 55 x 100 x 45.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 55 mm |
| Outer diameter D | 100 mm |
| Width B | 45.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 190 kN |
| Basic static load rating C0 | 212 kN |
| Fatigue load limit Pu | 24 kN |
| Reference speed (thermal) | 4500 rpm |
| Limiting speed (mechanical) | 6700 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1450 g |
| Manufacturer designation | SKF 30211/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 | 2.165 in |
|---|---|
| Outer diameter D | 3.937 in |
| Width B | 1.791 in |
| ISO bore code | 11 |
| Radial section height (D−d)/2 | 22.5 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) | 7 of 35 |
| Bore above smallest matched-df-series size | 30 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30211 | 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. |
| 30211-NTN | NTN | 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 30211-DF model number is decoded
Catalogue mass 1450 g covers both bearings and the ground spacer of 30211-DF; keep the set complete — substituting one bearing or a non-ground spacer destroys the factory clearance. Journal and housing interface: the 55 mm bore takes a k5 shaft seat and the 100 mm outside diameter pairs with an H7 housing bore; the 45.5 mm width defines shoulder depth and the 1450 g mass is the dead load in thermal-growth calculations. Setting note for 30211-DF: the axial clearance is set at the factory by selective spacer grinding for the /DF execution; in service, re-checking end play after the first thermal cycle catches seating relaxation before it becomes roller skid. Lubrication for the pair should be sized against the combined 45.5 mm width and 1450 g mass: two roller sets sweep twice the contact area of a single bearing of the same bore.The SKF 30211/DF is a 55×100×45.5 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.Digit by digit, 30211-DF reads as the ISO 355 base bearing 30211 supplied as a face-to-face (X) matched pair matched pair (/DF); the 55 mm bore and 100 mm OD are per-bearing, the 45.5 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 45.5 mm overall width of 30211-DF is the axial space the pair occupies.
Typical equipment & failure modes
Common applications
- automotive and light-truck wheel hubs
- industrial gearbox shafts and reducers
- differential and pinion drives
- axle-boxes in material-handling equipment
Known failure patterns
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- roller large-end smearing against the cone rib after EP lubricant film failure
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- hard-particle indentation of the tapered raceway in unfiltered oil
- grease degradation after long shelf storage without rotation or re-greasing
Selection pitfalls — read before you substitute
- Clamp the 30211-DF pair axially through the cones, never through the rollers; pressing force across the roller complement brinells the raceways of both bearings at once.
- Clamp the 30211-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 30211-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 190/212 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 30211/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 30211-DF?
The SKF 30211/DF is a matched pair of single-row tapered roller bearings in face-to-face (X) matched pair arrangement with 55 mm bore, 100 mm outer diameter and 45.5 mm overall width (2.165 × 3.937 × 1.791 in). From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 190 kN, C0 212 kN, fatigue load limit Pu 24 kN, reference speed 4,500 r/min, limiting speed 6,700 r/min, mass about 1.45 kg.
What does the /DF suffix on 30211-DF mean?
The base 30211 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 30211-DF for one bearing or the pair?
They are for the complete matched pair: C 190 kN dynamic and C0 212 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 30211 table values.
Can 30211-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 55 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 55 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.