30228T106-DB bearing: complete specifications & equivalents
The 30228T106-DB is a ISO 355 radial bearing sized 140 x 250 x 106 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 | 106 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 | 19000 g |
| Manufacturer designation | SKF 30228T106/DB |
| 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-db-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 9.843 in |
| Width B | 4.173 in |
| ISO bore code | 06 |
| Radial section height (D−d)/2 | 55 mm |
| Smallest bore in matched-db-series | 35 mm |
| Largest outer diameter in matched-db-series | 480 mm |
| Width range across matched-db-series | 41.5–288 mm |
| Bore position in matched-db-series (smallest first) | 19 of 30 |
| Bore above smallest matched-db-series size | 105 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30228T106 | 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 30228T106-DB model number is decoded
A matched /DB 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.SKF 30228T106/DB belongs to the SKF matched tapered-roller range — the 140 mm bore entry in back-to-back (O) matched pair arrangement, dimensioned 250 mm OD and 106 mm overall width for the pair.On the SKF nameplate, 30228T106-DB reads as base 30228T106 in a /DB matched execution — the suffix is part of the order number because a matched set is ground for a specific axial clearance and cannot be assembled from loose single bearings. In the back-to-back (O) arrangement the load lines diverge toward the shaft axis, giving the pair a wide effective spread: 30228T106-DB resists overturning moments and tilting loads stiffly, which is why O-sets are preferred for gearbox output shafts and pinion supports. Dividing the pair C 773 kN by the 140 mm bore gives 5.52 kN per millimetre of journal for the complete arrangement — a density metric that compares matched sets across the back-to-back (O) matched pair family. Journal and housing interface: the 140 mm bore takes a m6 shaft seat and the 250 mm outside diameter pairs with an H7 housing bore; the 106 mm width defines shoulder depth and the 19000 g mass is the dead load in thermal-growth calculations. Spacer discipline: the spacer between the two bearings of 30228T106-DB is ground to the individual set — it carries a serial link to the pair, so never swap spacers between sets of the same designation.
Typical equipment & failure modes
Common applications
- marine propulsion gearboxes
- large industrial mixer shafts
- offshore winch and drawworks drums
- large crusher and mineral-processing drives
Known failure patterns
- false brinelling on idle paired sets exposed to machine vibration
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- 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
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Spacer faces must stay parallel within the set's own tolerance; a tilted spacer in 30228T106-DB concentrates reversing thrust on one bearing and shows up as one-sided raceway wear.
- Setting is built into 30228T106-DB; the classic field error is re-adjusting a matched pair as if it were two loose single bearings, which destroys the /DB clearance class.
- Replace 30228T106-DB as a complete set: pairing a new bearing with a worn partner leaves the clearance undefined even when the designation matches.
- 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 30228T106/DB designation when purchasing — base-number-only orders are ambiguous across executions and variants.
Frequently asked questions
What are the dimensions and catalogue data of 30228T106-DB?
The SKF 30228T106/DB is a matched pair of single-row tapered roller bearings in back-to-back (O) matched pair arrangement with 140 mm bore, 250 mm outer diameter and 106 mm overall width (5.512 × 9.843 × 4.173 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 19.00 kg.
What does the /DB suffix on 30228T106-DB mean?
The base 30228T106 is the ISO 355 single-row bearing; the /DB suffix marks the matched-set execution — the arrangement (back-to-back (O)), 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 30228T106-DB 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 30228T106 table values.
Can 30228T106-DB 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 back-to-back (O) matched set be chosen?
Choose the back-to-back (O) set where moment stiffness dominates — pinion supports, gearbox output shafts, crane sheaves. The diverging load lines give the widest effective spread 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.