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 |
|---|---|
| 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 | 2026-09-24 |
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 | 10 mm |
| Largest outer diameter in 6300-series | 400 mm |
| Width range across 6300-series | 11–78 mm |
| Bore position in 6300-series (smallest first) | 2 of 30 |
| Bore above smallest 6300-series size | 2 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6301 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 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 6301 model number is decoded
In the 6300-series (ISO 15 diameter series 3) the last two digits encode the bore: 6301 carries bore code 01 = 12 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 37 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 12 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. 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
- instrument drives
- fractional-horsepower electric motors
- domestic appliances
- power tools
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
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 series gains rating at 12 mm bore through a 37 mm OD and 12 mm width; the heavier rolling elements also trade away some speed versus a 6201.
- The open 6301 has no lubricant retention: grease escapes and contaminants migrate straight into the 12×37×12 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- 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.
- Do not quieten a noisy bearing by preloading it: the 6300-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- 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. Geometry-based estimated mass is about 59 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
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 does no suffix on 6301 mean?
A bare 6301 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 6300 compare with other series at the same 12 mm bore?
The '3' is the medium diameter series: 37×12 mm, 12.5 mm radial section at 12 mm bore, carrying more load than a 6201 but needing a larger housing bore and giving up some speed.
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) 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 2026-09-24. Read our editorial & correction policy.