30328 bearing: complete specifications & equivalents
The 30328 is a ISO 355 radial bearing sized 140 x 300 x 67.75 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 | 300 mm |
| Width B | 67.75 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 787 kN |
| Basic static load rating C0 | 950 kN |
| Fatigue load limit Pu | 93 kN |
| Reference speed (thermal) | 1700 rpm |
| Limiting speed (mechanical) | 2200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 20500 g |
| Manufacturer designation | SKF 30328 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB); 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 & 30300-series range
| Bore d | 5.512 in |
|---|---|
| Outer diameter D | 11.811 in |
| Width B | 2.667 in |
| ISO bore code | 28 |
| Radial section height (D−d)/2 | 80 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 24 of 32 |
| Bore above smallest 30300-series size | 125 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30328 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 355 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 30328 model number is decoded
In SKF catalogue PUB BU/P1 17000, 30328 appears as SKF 30328: an open, single-row tapered roller bearing in the heavy-OD section of the 30300 dimension series, supplied with a pressed-steel cage as standard.Reading the designation: the leading 3 marks a single-row tapered roller bearing, the 03 is the ISO 355 diameter/width series (heavy-OD section), and the last two digits encode the 140 mm bore; the 300 mm OD and 67.75 mm width follow the ISO 355 general plan. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. 2GB); it is the dimensional series, not a separate part number. Selection arithmetic: the C0/C ratio is about 1.21 (static 950 kN against dynamic 787 kN), typical of a tapered roller sized for axial capacity, and the 93 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. For a 140 mm shaft the usual cone seat is m6 with an H7 housing when the inner ring rotates; arrange two 30328 bearings as a set for two-direction location and set clearance from the load diagram, never from assembly feel.
Typical equipment & failure modes
Common applications
- heavy-duty rolling-mill gearboxes
- large crusher and mineral-processing drives
- wind-turbine main shafts
- marine propulsion gearboxes
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- grease degradation after long shelf storage without rotation or re-greasing
Selection pitfalls — read before you substitute
- At 140 mm bore the cone mass is high enough that cocking during mounting damages the cage and rib; guide the ring square, confirm seat contact around the full circumference, and re-check setting after the first thermal cycle of the paired set.
- The 303 series at 140 mm bore (300×67.75 mm) carries a larger OD and higher capacity than 30228 at the same bore; the bigger section runs hotter, so re-check the 2,200 r/min speed ceiling and shoulder diameters before substituting.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 30328 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 30328 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- Catalogue reference speed and limiting speed are different limits: the 1,700 r/min reference is a thermal criterion under load, while the 2,200 r/min limiting value is the mechanical ceiling — observe both.
- The 787/950 kN ratings are SKF catalogue 17000 values for the basic 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 and re-verify for critical drives.
- SKF lists several executions of 30328 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30328 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30328?
The SKF 30328 is a single-row tapered roller bearing with 140 mm bore, 300 mm outer diameter and 67.75 mm width (5.512 × 11.811 × 2.667 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 787 kN, C0 950 kN, fatigue load limit Pu 93 kN, reference speed 1,700 r/min, limiting speed 2,200 r/min, mass about 20500 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30328 bore code work?
The last two digits of 30328 are bore code 28, so 28 × 5 = 140 mm bore. The 300 mm OD and 67.75 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30328 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 03 is the ISO 355 series (heavy-OD section). The SKF catalogue lists the ISO 355 dimension-series code after the bare number. A steeper-contact-angle variant (B suffix) is a different order number and is not interchangeable with the basic execution.
Can a single 30328 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 30328 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 30328 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB on 2026-09-26. Read our editorial & correction policy.