In a message dated 7/5/2002 12:20:50 AM Eastern Daylight Time, Steve@sburl.com writes:
> All the discussion about Campi bearings reminded me that what I had actually
> heard was the same as Tom said below--namely that Campy used grade 25
> bearings (I heard SKF) that had been matched to create sets that were of
> much closer diameter tolerances than would otherwise be found in grade 25
> bearings. My experience indicated that the Campi bearing sets built up
> smoother running parts, so I always cleaned, inspected and reinstalled
> Campy bearings, considering their replacement with new, but generic balls a
> downgrade.
>
Grade 25 is pretty darn good. Sphericity: .000025", allowable diameter variation: .00005". Maybe the Campy sets are matched, or maybe they came out of same batch which would sort of constitute being matched. I don't think replacing the worn balls is really the way I would go. Because they started out as high quality balls does not mean they're still round as they were when they were new. In the scheme of things balls are still cheap. I take them out and after looking for damage throw them in the scrap can.
Go to McMaster-Carr's website and search for balls, click on Chrome Steel
Balls, select a size and there on the page is a link to a pdf file showing a
chart of grade and tolerances. http://www.mcmaster.com/
Pete Geurds
Douglassville, PA