On 2007-10-29, (Tom) tom wrote:

I doubt that Fafnir would mislabel even skate bearings. I think that I
will buy those fake "ABEC 7" skate bearings, and will try to measure
their balls' concentricity.

i
None of the major manufacturers will mislabel any bearings and in fact
strive to make everything as close to the middle of the tolerance
range as possible which is why bearings sold as ABEC-1 will usually
meet ABEC-3 standards (from the majors). DuPont did a comparative
study between the largest bearing manufacturers in the world and
checked manufacturing processes, quality control procedures,
metallurgy etc. and ranked them accordingly. NTN was determined to
make the highest quality bearing followed by NSK, FAG and SKF in that
order. Fafnir wasn't large enough at the time to be considered but
they do make a fine bearing (as do all of the above). All make high
quality bearings that meet or exceed the standards but there was a
slight variation in the adherence to the center of the tolerance
range, concentricity etc. This is not necessarily true of some of the
"off brands".

I spent approximately $7 and will soon receive those "abec 7" skate
bearings. I will then try to measure concentricity of their balls when
I receive them in a few days.

i