6303 bearing: complete specifications & equivalents
The 6303 is a ISO 15 radial bearing sized 17 x 47 x 14 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Bore diameter d | 17 mm |
| Outer diameter D | 47 mm |
| Width B | 14 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 | 14.3 kN |
| Basic static load rating C0 | 6.55 kN |
| Fatigue load limit Pu | 0.275 kN |
| Reference speed (thermal) | 34000 rpm |
| Limiting speed (mechanical) | 22000 rpm |
| Operating temperature | -40 to +150 °C |
| Mass | 110 g |
| Manufacturer designation | SKF 6303 |
| 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 | 0.669 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.551 in |
| ISO bore code | 03 |
| Radial section height (D−d)/2 | 15 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) | 4 of 30 |
| Bore above smallest 6300-series size | 7 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6303-2RS | GENERIC-ISO | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 17×47×14 mm envelope per ISO 15; seal variant differs (OPEN vs 2RS) — confirm sealing suits the duty. |
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 6303 model number is decoded
In the 6300-series (ISO 15 diameter series 3) the last two digits encode the bore: 6303 carries bore code 03 = 17 mm. Codes 00–03 follow the 10/12/15/17 mm exception table rather than code × 5. Outside diameter 47 mm and width 14 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 17 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
- 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: 6303 fits a 17 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 17 mm bore through a 47 mm OD and 14 mm width; the heavier rolling elements also trade away some speed versus a 6203.
- The open 6303 has no lubricant retention: grease escapes and contaminants migrate straight into the 17×47×14 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 6303 units.
- A 17 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 6303 needs external sealing and application-supplied lubrication; in the SKF catalogue the protected variants are separate order numbers 6303-2Z (shields) and 6303-2RSH (contact seals), not suffix-free 6303.
- The 14.3/6.55 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 6303 bearing?
A 6303 deep-groove ball bearing has a 17 mm bore, 47 mm outer diameter and 14 mm width (0.669 × 1.85 × 0.551 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields. Geometry-based estimated mass is about 108 g for a steel-cage unit; catalogue masses vary slightly with seal and cage design.
Why does 6303 not follow the bore-code × 5 rule?
Codes 00–03 use the exception table (10, 12, 15 and 17 mm): 6303 with code 03 has a 17 mm bore. The code × 5 convention starts at code 04 (20 mm).
What does no suffix on 6303 mean?
A bare 6303 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 17 mm bore?
The '3' is the medium diameter series: 47×14 mm, 15.0 mm radial section at 17 mm bore, carrying more load than a 6203 but needing a larger housing bore and giving up some speed.
What is the SKF designation and catalogue data for 6303?
In the SKF Rolling Bearings catalogue this size is listed as 6303 — the open (unsealed) execution, 17×47×14 mm per ISO 15. Quoted values: C 14.3 kN, C0 6.55 kN, Pu 0.275 kN, limiting speed 22000 r/min, mass 110 g. Brand suffixes (2Z, 2RSH) differ from the industry-neutral spelling 6303.
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.