If you only need a radius/chamfer and not a width decrease try the following:
1. clamp bearing shells around a block of wood or plastic that is narrower than the bearing.
2. locate a pc. of 1/4” cold rolled bar.
3. using a hacksaw, carefully cut a slit in one end about 3/4” long.
4. fold a 1” X 2” pc. of emery cloth lengthwise and insert in slit.
5. mount rod in a die grinder.
6. hold die grinder parallel to bearing centerline and bump the paper against the ends until desired radius is generated. Coarser paper will take off material more rapidly so use caution and start with 220 grit or finer.
