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Candidates and diagrams
How to use it
Choose from catalogue. Enter the shaft diameter, any envelope limits, the loads and the speed: the tool compares all the 60, 62 and 63 series deep groove ball bearings with that bore and proposes the most compact one that reaches the required life with the desired static safety.
SKF catalogue data. For angular contact, self-aligning, tapered or cylindrical roller bearings, copy from the SKF catalogue (or another manufacturer's) the designation, dimensions, load ratings C and C0, fatigue load limit Pu and, where needed, the e and Y factors. The tool applies the equivalent load rules for the chosen type.
With the load cycle you can describe up to three operating conditions with their percentage of time: equivalent load and speed are calculated with the average weighted on the number of revolutions.
ISO 281 method
It's the same method SKF uses for the SKF rating life, where the aISO factor becomes aSKF. The oil viscosity at operating temperature is derived from the ISO VG grade with the Walther equation; for greases, enter the base oil grade.
Required life by machine type
Reference values for the specification life, used as a starting point in manufacturers' catalogues:
- Household appliances, instruments, agricultural machinery: 300–3000 hours
- Machines for intermittent use (portable tools, hoists, construction machinery): 3000–8000 hours
- Machines for short but highly reliable use (lifts, cranes for packaged goods): 8000–12 000 hours
- Machines for 8 hours a day, not always at full load (gearboxes, industrial electric motors): 10 000–25 000 hours
- Machines for 8 hours a day at full load (machine tools, fans, conveyors): 20 000–30 000 hours
- Continuous 24-hour operation (pumps, compressors, rolling mills, textiles): 40 000–50 000 hours
- Hydroelectric plants, rotary kilns, ships: 60 000–100 000 hours; paper mills and large motors over 100 000 hours
Catalogue values and limits
The built-in catalogue gives ISO dimensions and reference load ratings for SKF deep groove ball bearings in the 60, 62 and 63 series, with normal clearance and no seals. They are indicative values: before ordering, compare them with the SKF online catalogue, which also gives reference and limiting speeds, masses and the shielded (2Z) or sealed (2RS1) variants, which have lower limiting speeds.
The tool doesn't assess fits with shaft and housing, operating clearance, heating, grease lubrication and relubrication intervals, or arrangements with several bearings (pairs of angular contact or tapered bearings with induced axial forces). For the complete sizing of a bearing arrangement, if you need help, contact us for a consultation. SKF is a registered trademark of the SKF Group; this site is not affiliated with SKF.
FAQ
What's the difference between L10h and Lnm?
L10h is the basic life: 90% of a group of identical bearings reaches or exceeds it, considering load only. Lnm corrects the basic life for reliability, lubrication and contamination: with a good oil film and clean lubricant it can be several times higher, in a dirty environment much lower.
What is the viscosity ratio κ?
It's the ratio between the lubricant's actual viscosity at operating temperature and the minimum viscosity needed to separate the rolling elements from the raceways. With κ greater than 1 the film is adequate; below 1 life drops rapidly, and below 0.1 the calculation is no longer valid.
Why is the fatigue load limit Pu needed?
Below Pu the bearing material, under ideal conditions, doesn't fatigue. The ratio ec·Pu/P enters the aISO factor: lightly loaded, well-lubricated bearings can have very high modified lives, capped at 50 times the basic life.
Can I use data from other manufacturers?
Yes. The method is that of ISO 281: with the "SKF catalogue data" tab you can enter C, C0 and Pu from any manufacturer. Bear in mind that the values for bearings with the same designation may differ from one manufacturer to another.
Can a deep groove ball bearing take axial loads?
Yes, even in both directions, up to about half the static load rating C0 (a quarter for small, light bearings). For high axial loads, angular contact ball or tapered roller bearings are used.