30334 bearing: complete specifications & equivalents
The 30334 is a ISO 355 radial bearing sized 170 x 360 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 170 mm |
| Outer diameter D | 360 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 1103 kN |
| Basic static load rating C0 | 1340 kN |
| Fatigue load limit Pu | 129 kN |
| Reference speed (thermal) | 1400 rpm |
| Limiting speed (mechanical) | 1800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 34500 g |
| Manufacturer designation | SKF 30334 |
| 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 | 6.693 in |
|---|---|
| Outer diameter D | 14.173 in |
| Width B | 3.15 in |
| ISO bore code | 34 |
| Radial section height (D−d)/2 | 95 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) | 27 of 32 |
| Bore above smallest 30300-series size | 155 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30334 | 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 30334 model number is decoded
The SKF 30334 is a 170×360×80 mm single-row tapered roller bearing — the heavy-OD section entry in the 30300 series, with an asymmetric raceway cut for thrust capacity and separable mounting.On the SKF nameplate, 30334 follows the ISO 355 convention: 3 for the tapered-roller type, 03 for the heavy-OD section, final digits 34 for the 170 mm bore. 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 1340 kN against dynamic 1103 kN), typical of a tapered roller sized for axial capacity, and the 129 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. Fit selection follows the rotating ring — interference on a rotating cone — and two 30334 units are required to take reversing thrust; keep the induced axial load inside the rated capacity when calculating the pair.
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
- axial overload spalling at the roller-rib contact beyond the single-row thrust rating
- preload loss as the mounted pair relaxes, letting rollers skid and smear the raceways
- 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
Selection pitfalls — read before you substitute
- At 170 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 170 mm bore (360×80 mm) carries a larger OD and higher capacity than 30234 at the same bore; the bigger section runs hotter, so re-check the 1,800 r/min speed ceiling and shoulder diameters before substituting.
- A single 30334 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- Setting is a design value, not an assembly feel: excessive preload in the 30334 pair raises operating temperature and can trigger thermal runaway, while too little lets the rollers skid and smear the raceway under light load.
- The 30334 shares its ISO 355 envelope with other tapered bearings of the same code but is not a drop-in replacement for a ball bearing: it cannot run effectively under pure radial load without a minimum axial load, and a deep-groove bearing cannot replace its combined-load duty.
- The 1103/1340 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 30334 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30334 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30334?
The SKF 30334 is a single-row tapered roller bearing with 170 mm bore, 360 mm outer diameter and 80 mm width (6.693 × 14.173 × 3.15 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 1103 kN, C0 1340 kN, fatigue load limit Pu 129 kN, reference speed 1,400 r/min, limiting speed 1,800 r/min, mass about 34500 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30334 bore code work?
The last two digits of 30334 are bore code 34, so 34 × 5 = 170 mm bore. The 360 mm OD and 80 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30334 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 30334 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 30334 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 30334 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.