Pat Dewitt mentions using inexpensive imported bearings in his Duo-Art
pump, bearings that cost one-tenth of the cost of USA-made bearings.
As far as I know there are no cheap USA bearings, that market being
left to the Chinese.  There are also fine bearings made in Germany
and Switzerland etc.

Bearings are graded according to precision of manufacture.  Bearings
are rated by the ABEC standard.  Although there are a lot of details
not covered by this spec it is adequate for all but very specialized
applications.  Higher ABEC numbers are more precisely made and can
run at higher speeds.  For something like the Duo-Art pump, the lowest
classification is probably adequate and anything better is really just
gilding the lily.

What is probably more important than ABEC grade is that the bearings
have good seals and permanent lubrication or that they be lubricated
appropriately if not sealed.  I have had good luck using Chinese
ABEC 5 bearings in a number of low speed applications.  Better grade
bearings are required for high speeds (more than 10,000 RPM, for
example) or where runout is not tolerable.

I bought a box of random bearings at a garage sale many years ago and
am still finding use for them occasionally.  There were a few bearings
that were pretty normal looking but had stick-on labels saying to use
them only in one machine as they were high precision high speed bearings
and not for general use.  I looked up these bearings on-line a while
ago and saw that they cost something like $250 each compared to cheap
ones of the same size.  If I ever need to run a one-inch shaft at
30,000 RPM, I have the bearings!  Unfortunately they are a bit too
large for the Duo-Art pump. :)

Spencer Chase
Garberville, California