6301-ZZ bearing: complete specifications & equivalents
The 6301-ZZ is a ISO 15 radial bearing sized 12 x 37 x 12 mm (bore x OD x width) with ZZ sealing. 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 | ZZ |
| 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) | 22000 rpm |
| Operating temperature | -30 to +120 °C |
| Mass | 63 g |
| Manufacturer designation | SKF 6301-2Z |
| 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 (ZZ 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; seal variant (ZZ vs OPEN) and load ratings differ — confirm sealing and rating 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; catalogue load ratings differ by >10% — re-rate the application before substituting. |
| 6301 | ISO 15 | verify Commonly quoted cross reference; confirm against the target catalog before ordering. | ISO 15 boundary-dimension envelope; seal suffix convention varies by brand (2RS / DDU / LLU / 2RSR) — verify seal design and temperature range before substituting. |
| 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 (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6301-NSK | NSK | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 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 (ZZ vs RSR) — confirm sealing suits the duty. |
| 6301-ZZ-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. |
| 6301-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (ZZ vs 2RS) — confirm sealing suits the duty. |
| 6301-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 12×37×12 mm envelope per ISO 15; seal variant differs (ZZ vs OPEN) — confirm sealing suits the duty. |
| 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 (ZZ vs RSR) — confirm sealing suits the duty. |
| 6301-ZZ-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. |
| 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-ZZ model number is decoded
6301-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. 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. SKF's own suffix is 2Z (this page's industry-neutral spelling is -ZZ); catalogue number 6301-2Z.
Typical equipment & failure modes
Common applications
- domestic appliances
- power tools
- small fans and blowers
- garden equipment
Known failure patterns
- fine-particle abrasion when non-contact shields let dust past in dirty duty
- grease aging in the shield-for-life cavity with no relubrication path
- edge loading from shaft deflection or housing misalignment
- rolling-contact fatigue spalling after the rated L10 life is exceeded
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.
- Do not wash 6301-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
- Shielded 6301-ZZ units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
- Vibration during standstill brinells the raceways of a 12 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.
- Shaft and housing fillets must clear the bearing chamfer so the 12 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- SKF spells the shielded version 6301-2Z (one shield: 6301-Z), not "-ZZ": the suffix language differs by brand even though the ISO envelope is identical, so quote the brand designation when ordering.
- The single-shield execution 6301-Z is a distinct order number in catalogue 17000: it suits open gears or oil-bath arrangements where the unshielded face faces the lubricant, and it is not interchangeable with the double-shield 6301-2Z for high-contamination positions.
- 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-ZZ bearing?
A 6301-ZZ 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 fitted with two non-contact metallic shields.
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 the ZZ suffix on 6301-ZZ mean?
ZZ means two non-contact sheet-metal shields, one each side. They retain factory grease and block coarse particles with little friction, but do not seal against liquids, fine dust or pressure washing.
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-ZZ?
In the SKF Rolling Bearings catalogue this size is listed as 6301-2Z — two non-contact sheet-metal shields, 12×37×12 mm per ISO 15. Quoted values: C 10.1 kN, C0 4.15 kN, Pu 0.176 kN, limiting speed 22000 r/min, mass 63 g. Brand suffixes (2Z, 2RSH, 2RSL) differ from the industry-neutral spelling 6301-ZZ.
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.