6301 bearing: complete specifications & equivalents
The 6301 is a ISO 15 radial bearing sized 12 x 37 x 12 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 12 mm |
| Outer diameter D | 37 mm |
| Width B | 12 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 10.1 kN |
| Basic static load rating C0 | 4.15 kN |
| Fatigue load limit Pu | 0.176 kN |
| Reference speed (thermal) | 45000 rpm |
| Limiting speed (mechanical) | 28000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 60 g |
| Manufacturer designation | SKF 6301 |
| Standard | ISO 15 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018) |
| Last verified | 2026-09-25 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-24
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 | 0.472 in |
|---|---|
| Outer diameter D | 1.457 in |
| Width B | 0.472 in |
| ISO bore code | 01 |
| Radial section height (D−d)/2 | 12.5 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) | 6 of 40 |
| Bore above smallest 6300-series size | 10 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6301-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant (OPEN vs 2RS) and load ratings differ — confirm sealing and rating before substituting. |
| 6301-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6301-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant (OPEN vs ZZ) and load ratings differ — confirm sealing and rating before substituting. |
| 6301 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 6301-2RS-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6301-NSK | NSK | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6301-RSR-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 6301-ZZ-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 6301-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
| 6301-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Identical ISO 15 envelope, seal and ratings band — standard interchange; re-verify precision class and clearance per supplier. |
| 6301-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs RSR) — confirm sealing suits the duty. |
| 6301-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (OPEN vs ZZ) — confirm sealing suits the duty. |
| 7301 | SKF | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | — |
| W6301-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6301-2RS1 shares the 12×37×12 mm envelope but rates differently (10.1/4.15 kN vs 8.32/4.15 kN) — not a load-rating equivalent. |
| W6301-ZZ | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6301-2Z shares the 12×37×12 mm envelope but rates differently (10.1/4.15 kN vs 8.32/4.15 kN) — not a load-rating equivalent. |
| W6301 | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | SKF stainless execution W 6301 shares the 12×37×12 mm envelope but rates differently (10.1/4.15 kN vs 8.32/4.15 kN) — 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 6301 model number is decoded
6301 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), its bore code 01 comes from the 10/12/15/17 mm exception table, giving a 12 mm bore; the 37 mm outside diameter and 12 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 12 mm shaft under normal load, catalogue practice seats it on a j5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the SKF catalogue this open execution carries the bare designation; protected variants are ordered separately as -2Z and -2RSH.
Typical equipment & failure modes
Common applications
- domestic appliances
- power tools
- small fans and blowers
- garden equipment
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- electrical pitting in VFD-driven motors without grounding protection
- raceway smearing under marginal lubrication at start-up
Selection pitfalls — read before you substitute
- Bore codes 00–03 use the exception table: 6301 fits a 12 mm shaft — the code × 5 mnemonic does not apply below code 04 (it would imply 0 mm for code 00).
- The 63xx medium section at 12 mm bore gains dynamic rating through larger rolling elements on a 37 mm OD; the penalty is mass and a lower limiting speed than the 6201 — do not specify it for speed-critical shafts.
- Storage matters for open bearings: 6301 leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6301 units.
- Never mix components between two 6301 units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
- A 12 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
- The open 6301 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6301-2Z (shields) and 6301-2RSH (contact seals), not suffix-free 6301.
- The 10.1/4.15 kN ratings here are SKF Explorer-class figures from catalogue PUB BU/P1 17000/1 EN (Oct 2018); SKF can revise internal geometry and ratings without changing the designation, so treat the catalogue version and date as part of the specification and re-verify for critical drives.
Frequently asked questions
What are the dimensions of a 6301 bearing?
A 6301 deep-groove ball bearing has a 12 mm bore, 37 mm outer diameter and 12 mm width (0.472 × 1.457 × 0.472 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How should 6301 be mounted?
Apply the mounting force to the ring being fitted: on a 12 mm shaft seat the press load must pass through the inner-ring face only. A fitting sleeve and an arbor press are normally sufficient at this size. Never strike the outer ring, the cage or the seals.
What lubrication does 6301 need?
The open 6301 is lubricated by the application; a NLGI 2 lithium-soap grease filled to roughly 25–35% of the free volume is the common choice, with a defined relubrication interval.
Why does 6301 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 6301 with code 01 has a 12 mm bore. The code × 5 convention starts at code 04 (20 mm).
What is the SKF designation and catalogue data for 6301?
In the SKF Rolling Bearings catalogue this size is listed as 6301 — the open (unsealed) execution, 12×37×12 mm per ISO 15. Quoted values: C 10.1 kN, C0 4.15 kN, Pu 0.176 kN, limiting speed 28000 r/min, mass 60 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6301.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018) on 2026-09-25. Read our editorial & correction policy.