30315 bearing: complete specifications & equivalents
The 30315 is a ISO 355 radial bearing sized 75 x 160 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 75 mm |
| Outer diameter D | 160 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 301 kN |
| Basic static load rating C0 | 290 kN |
| Fatigue load limit Pu | 34 kN |
| Reference speed (thermal) | 3400 rpm |
| Limiting speed (mechanical) | 4300 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3500 g |
| Manufacturer designation | SKF 30315 |
| 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 | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.575 in |
| ISO bore code | 15 |
| Radial section height (D−d)/2 | 42.5 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) | 14 of 32 |
| Bore above smallest 30300-series size | 60 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30315 | 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 30315 model number is decoded
SKF 30315 belongs to the SKF single-row tapered roller range — the 75 mm bore entry in the 30300 series, dimensioned 160 mm OD and 40 mm wide to the ISO 355 boundary plan.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 75 mm bore; the 160 mm OD and 40 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 0.96 (static 290 kN against dynamic 301 kN), typical of a tapered roller sized for axial capacity, and the 34 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. Specify pairs rather than single units wherever thrust reverses: the tapered contact of 30315 generates an induced axial load under radial force, and an unpaired bearing on a reversing shaft will run slack and fret its seat.
Typical equipment & failure modes
Common applications
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
- rolling-mill auxiliary drives
- crane sheave and hoist 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
- false brinelling on idle paired sets exposed to machine vibration
- roller large-end smearing against the cone rib after EP lubricant film failure
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- rolling-contact fatigue spalling after the rated L10 life is exceeded
Selection pitfalls — read before you substitute
- Mount the 75 mm bore 30315 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 75 mm bore (160×40 mm) carries a larger OD and higher capacity than 30215 at the same bore; the bigger section runs hotter, so re-check the 4,300 r/min speed ceiling and shoulder diameters before substituting.
- O (back-to-back) pairs are stiffer against moments, X (face-to-face) pairs tolerate misalignment and thermal growth better; choosing the arrangement from the 2D drawing rather than the actual shaft thermal expansion is a common 30315 mounting error.
- The tapered contact angle creates an induced axial load under pure radial force; include it in the 30315 rating calculation (and account for it in both bearings of a pair) or the unloaded bearing skids its rollers.
- Shaft and housing fillets must clear the bearing chamfer so the 40 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 301/290 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 30315 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30315 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30315?
The SKF 30315 is a single-row tapered roller bearing with 75 mm bore, 160 mm outer diameter and 40 mm width (2.953 × 6.299 × 1.575 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 301 kN, C0 290 kN, fatigue load limit Pu 34 kN, reference speed 3,400 r/min, limiting speed 4,300 r/min, mass about 3500 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30315 bore code work?
The last two digits of 30315 are bore code 15, so 15 × 5 = 75 mm bore. The 160 mm OD and 40 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30315 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 30315 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 30315 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 30315 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.