30312 bearing: complete specifications & equivalents
The 30312 is a ISO 355 radial bearing sized 60 x 130 x 33.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 60 mm |
| Outer diameter D | 130 mm |
| Width B | 33.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 208 kN |
| Basic static load rating C0 | 196 kN |
| Fatigue load limit Pu | 23.6 kN |
| Reference speed (thermal) | 4300 rpm |
| Limiting speed (mechanical) | 5300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 1950 g |
| Manufacturer designation | SKF 30312 |
| 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 | 2.362 in |
|---|---|
| Outer diameter D | 5.118 in |
| Width B | 1.319 in |
| ISO bore code | 12 |
| Radial section height (D−d)/2 | 35 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) | 11 of 32 |
| Bore above smallest 30300-series size | 45 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30312 | 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 30312 model number is decoded
30312 is a single-row tapered roller bearing in the ISO 30300 dimension series: a separable cone-and-cup design for combined radial and one-direction axial load, listed by SKF in SKF catalogue PUB BU/P1 17000.Numbering ties the bearing to its envelope: 30312 means tapered-roller type 3, heavy-OD section series 03, 60 mm bore — which is why the 130×33.5 mm outline swaps dimensionally with other ISO 355 bearings of the same code. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. 2FB); it is the dimensional series, not a separate part number. Speed planning uses two different ceilings: 4,300 r/min thermal reference and 5,300 r/min mechanical limiting speed. Fit selection follows the rotating ring — interference on a rotating cone — and two 30312 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
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist gearboxes
- paper-machine and printing rolls
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
- roller large-end smearing against the cone rib after EP lubricant film failure
- false brinelling on idle paired sets exposed to machine vibration
- cage pocket scoring when the bearing starts cold with grease of too-high base-oil viscosity
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Mount the 60 mm bore 30312 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The 303 series at 60 mm bore (130×33.5 mm) carries a larger OD and higher capacity than 30212 at the same bore; the bigger section runs hotter, so re-check the 5,300 r/min speed ceiling and shoulder diameters before substituting.
- At the 208 kN rating of 30312, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 5,300 r/min speed end and heavier preload only where moment stiffness dominates.
- When the outer ring rotates, reverse the fit logic and provide cup location; the tapered contact of 30312 pushes the rings apart under load, so a non-located cup walks its seat even when the shaft is fixed.
- The pressed-steel cage is rated for standard industrial service; sustained running above the limiting speed or with degraded lubricant wears the cage pockets — inspect the cage at every relubrication interval.
- The 208/196 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 30312 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30312 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30312?
The SKF 30312 is a single-row tapered roller bearing with 60 mm bore, 130 mm outer diameter and 33.5 mm width (2.362 × 5.118 × 1.319 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 208 kN, C0 196 kN, fatigue load limit Pu 23.6 kN, reference speed 4,300 r/min, limiting speed 5,300 r/min, mass about 1950 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30312 bore code work?
The last two digits of 30312 are bore code 12, so 12 × 5 = 60 mm bore. The 130 mm OD and 33.5 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30312 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 30312 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 30312 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 30312 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.