On Sun, 28 Oct 2007 04:48:20 -0000, woodworker88
wrote:

On Oct 27, 12:40 pm, Ignoramus2057
wrote:

I had a long discussion with a particularly stubborn friend of mine
about this very topic.

ABEC 7 is the grade used for machine spindle bearings, and is
obscenely expensive (when the tolerances are held to +/- 0.0001",
you'd kinda expect it to be). Nearly all ABEC 7 bearings I've ever
encountered were tapered roller bearings.

Most of the ABEC - 7's will be Angular Contact Ball Bearings or Single
Row Deep Groove Ball Bearings.

The skateboard manufacturers just use it as a cool name, most skate
bearings are ABEC 3 at best. Most non-engineers aren't aware of the
real system.

Fafnir actually makes both real bearings (I think they're a subsidiary
of Timken now) as well as skate bearings. I have some Fafnir
machinery bearings, they're good stuff. Usually the shields on the
skate bearings are colored a bright color, the ones I have are either
green or red. The equipment bearings have black shields or are
unshielded.

Shields are usually left in their natural metallic color whereas seals
are colored with the colors denoting the material.