315 bearing: complete specifications & equivalents
The 315 is a ISO 15 radial bearing sized 75 x 160 x 37 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 | 37 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 125 kN |
| Basic static load rating C0 | 116 kN |
| Fatigue load limit Pu | 4.55 kN |
| Reference speed (thermal) | 7500 rpm |
| Limiting speed (mechanical) | 4800 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 3250 g |
| Manufacturer designation | 315 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-27 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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 & 300-series range
| Bore d | 2.953 in |
|---|---|
| Outer diameter D | 6.299 in |
| Width B | 1.457 in |
| ISO bore code | 15 |
| Radial section height (D−d)/2 | 42.5 mm |
| Smallest bore in 300-series | 25 mm |
| Largest outer diameter in 300-series | 190 mm |
| Width range across 300-series | 17–43 mm |
| Bore position in 300-series (smallest first) | 11 of 14 |
| Bore above smallest 300-series size | 50 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6315-RSR | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | NSK bearing NSK 6315VV on the same 75×160×37 mm envelope, but catalogue C/C0 differ (125/116 kN vs 125/77 kN) — envelope interchange only after a load check. |
| 6315-M | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 75×160×37 mm envelope as SKF 6315 M, but catalogue C/C0 differ (125/116 kN vs 119/76.5 kN) — envelope match only after a load check. |
| 315-ZZ | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 75×160×37 mm envelope and equivalent catalogue ratings; 315-2Z is the two non-contact shields execution of this size — boundary dimensions interchangeable, only the seal/shield/cage execution differs. |
| 6315 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 6315 shares the 75×160×37 mm envelope but catalogue C/C0 differ (125/116 kN vs 119/76.5 kN) — envelope match, not a load-rating equivalent. |
| 6315-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 6315-2Z shares the 75×160×37 mm envelope but catalogue C/C0 differ (125/116 kN vs 119/76.5 kN) — envelope match, not a load-rating equivalent. |
| 6315-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF SKF 6315-2RS1 shares the 75×160×37 mm envelope but catalogue C/C0 differ (125/116 kN vs 119/76.5 kN) — envelope match, not a load-rating equivalent. |
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 315 model number is decoded
315 is a filling-slot (notched-ring) deep-groove bearing in the legacy 300-series: the last two digits encode the bore: 315 carries code 15 = 75 mm (code × 5). The rings carry loading slots that allow extra balls during assembly, which is what gives the 75×160×37 mm envelope its C 125 kN and C0 116 kN ratings (Pu 4.55 kN). The open 315 carries no shields or seals and relies on application lubrication and external sealing. Limiting speed 4800 r/min, mass 3250 g. These bearings are built for high purely-radial loads at moderate speeds.
Typical equipment & failure modes
Common applications
- legacy machinery repairs
- slew drives
- material-handling winches
- slow heavy gearboxes
Known failure patterns
- spalling of the filling-slot edge when balls are hammered through the slot under heavy thrust loading
- dirt entering through the open slot area when external sealing is neglected
- electrical pitting in VFD-driven motors without shaft grounding
- edge loading from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Shields on 315 retain grease but do not seal against water; for wet farm duty add external lip seals rather than trusting the shield.
- Limiting speed is just 4800 r/min: filling-slot cages and the slot geometry run cooler below that — overspeed drives cage wear and smearing.
- Filling slots let more balls be packed into the 75×160 mm envelope, which is why 315 reaches C 125 kN — but the slots also mean the two rings separate when the balls align with them, so handle it as a loose-clearance design.
- The slots sit at one angular position: on 315, never pass the full radial load across the slot zone during mounting or the ring lip can crack.
- Filling slots let more balls be packed into the 75×160 mm envelope, which is why 315 reaches C 125 kN — but the slots also mean the two rings separate when the balls align with them, so handle it as a loose-clearance design.
- Clearance suffixes follow the seal code in the designation stack (e.g. 315-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
Frequently asked questions
What are the dimensions of 315?
Filling-slot bearing 315 measures 75×160×37 mm (2.953×6.299×1.457 in), about 3250 g.
What does the designation 315 mean?
It is the legacy 200/300 filling-slot numbering: series 300 and bore code 15 = 75 mm. Filling-slot bearings predate the 6xxx deep-groove spelling.
What is a filling-slot bearing?
The inner and outer rings each have a loading slot; when aligned, extra balls can be inserted, raising radial rating (C 125 kN for 315). The slots also make the rings separable.
Can 315 take axial load?
Very little: the filling slots interrupt the raceway shoulders, so thrust towards the open slot side can unload or jam the balls. Use a standard deep-groove 6xxx bearing for combined loads.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-27. Read our editorial & correction policy.