Most small shafts for linear bearings that I am familiar with are “case hardened.” Simply means the surface (well, maybe a tiny bit below) is what has been hardened. The metal below this “case” is softer. Having said that, I have yet to run across something like this that could not be cut with a sharp, new hacksaw blade and a few drops of oil or soapy water. 10mm should not take more than a minute or two.
As to abrasive wheels - you could use a cut off wheel fitted on to one of the Ryobi battery powered grinders. As someone else pointed out, the abrasive wheels cut through friction and do generate heat. I doubt it will distort the end that much, but I would test on a sample first. Since the ends of your rods will be supported in some sort of mount, if you can get the bearings on, you are not worried about the quality of the surface in the mount.
However you do it, you should be able to clean and face the ends in the machine shop lathe, using a carbide cutter.