6307-M bearing: complete specifications & equivalents
The 6307-M is a ISO 15 radial bearing sized 35 x 80 x 21 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 35 mm |
| Outer diameter D | 80 mm |
| Width B | 21 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 35.1 kN |
| Basic static load rating C0 | 19 kN |
| Fatigue load limit Pu | 0.815 kN |
| Reference speed (thermal) | 19000 rpm |
| Limiting speed (mechanical) | 17000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 540 g |
| Manufacturer designation | 6307 M |
| 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 & 6300-series range
| Bore d | 1.378 in |
|---|---|
| Outer diameter D | 3.15 in |
| Width B | 0.827 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 22.5 mm |
| Smallest bore in 6300-series | 2 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 3–95 mm |
| Bore position in 6300-series (smallest first) | 14 of 40 |
| Bore above smallest 6300-series size | 33 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6307-RSR | NSK | full Dimensions and internal design equivalent — standard interchange. | NSK counterpart NSK 6307VV on the same 35×80×21 mm envelope with ratings within 10 % — interchange after checking seal, cage and precision details on both pages. |
| W6307-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope, but the stainless and chrome-steel executions carry different catalogue ratings (35.1/19 kN vs 28.6/19 kN) — envelope match, not a load-rating equivalent; choose by corrosion versus load duty. |
| 307 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope as SKF 307, but catalogue C/C0 differ (35.1/19 kN vs 34.7/26.5 kN) — envelope match only after a load check. |
| 307-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×80×21 mm envelope as SKF 307-2Z, but catalogue C/C0 differ (35.1/19 kN vs 34.7/26.5 kN) — envelope match only after a load check. |
| 6307 | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6307 (open arrangement) shares the 35×80×21 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6307-ZZ | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6307-2Z (two non-contact shields) shares the 35×80×21 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
| 6307-2RS | SKF | full Dimensions and internal design equivalent — standard interchange. | SKF SKF 6307-2RSH (two contact elastomer seals) shares the 35×80×21 mm envelope with ratings within 10 % — execution variant of the same size; boundary dimensions interchangeable. |
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 6307-M model number is decoded
In the 6300-series, the last two digits encode the bore: 6307 carries code 07 = 35 mm (code × 5). The envelope is 35×80×21 mm (1.378×3.15×0.827 in) with a 22.5 mm radial section height, C 35.1 kN, C0 19 kN and Pu 0.815 kN. The open 6307 M carries no shields or seals and relies on application lubrication and external sealing. The M suffix identifies the machined brass cage execution, a separate order number from the pressed-steel version. Limiting speed 17000 r/min, catalogue mass 540 g.
Typical equipment & failure modes
Common applications
- centrifugal and positive-displacement pumps
- material-handling equipment
- industrial fans
- compressor drives
Known failure patterns
- contamination wear when the open arrangement is used without external seals
- lubricant starvation where no regreasing interval is maintained
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling once the catalogue L10 life is exceeded
Selection pitfalls — read before you substitute
- Clearance suffixes follow the seal code in the designation stack (e.g. 6307-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
- The fatigue load limit is 0.815 kN; it feeds the equivalent-mean-load check, not the basic life calculation — do not substitute one for the other.
- The M suffix on 6307-M denotes a machined brass cage: it is the choice for high speeds, marginal lubrication and shock/vibration duty, and it is temperature-tolerant where polymer cages are not — the 540 g quoted mass includes the heavier cage.
- Open 6307-M needs external sealing at the arrangement level; in dusty housings its life depends entirely on those external seals and the regreasing schedule.
- Plan a relubrication interval for 6307-M; run-to-failure on open deep-groove bearings is the dominant early-failure cause.
- Clearance suffixes follow the seal code in the designation stack (e.g. 6307-2Z/C3 in SKF spelling); no suffix means normal CN internal clearance.
Frequently asked questions
What are the dimensions of 6307-M?
The SKF 6307 M measures 35 mm bore × 80 mm OD × 21 mm width (1.378 × 3.15 × 0.827 in), mass about 540 g. It is open, with no shields or seals.
How does the bore code in 6307 work?
The final two digits of 6307 are bore code 07, multiplied by 5 to give 35 mm.
What is the difference between 6307-M and a same-bore 62-series bearing?
Section height differs: 6307-M has a 22.5 mm radial section and C 35.1 kN; always match d, D and B — same bore alone never makes two bearings interchangeable.
Which fits should I use for 6307-M?
With a rotating inner ring use roughly k5 on the shaft and H7 in the 80 mm housing; reverse the interference if the outer ring rotates.
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.