I need to cut some steel rods for use with 3d printer linear bearings. They are hardened chrome steel, and I’m wondering what I should use to cut them. I’m pretty sure there is a miter saw with a cutoff disk which would work, right? Or is there something better I should use?
These are the rods in question:
The blade in the miter saw is only for non-ferrous metal; do not use it to cut this. I would use the horizontal band saw, though the blade in it may not be in the best shape by now. You could also use the vertical band saw, if you’re cutting lengths less than 20". Dial in the correct speed and it should make short work of this. You’ll need a good grip to keep the rod from spinning.
Thanks, that’s good to know about the miter saw. My cutting lengths are all between 300 and 400 mm, so the vertical band saw should do the trick.
I’d use the lathe, a lot less heat so less likely to induce distortion since this is probably critical for your use.
Simple way to cut drill rod or ground rod, Use a steel abrasive disk. They are cheap. Cant use the lathe without a lot of effort. Saw blades are to soft. Cut off wheel is fast and accurate.
I used the big bandsaw in the metal shop and tapered the ends with the grinding wheel. It cuts accurately.
Be prepared to destroy or throw away a few of your lm8uu bearings.
If the piece your cutting is Hardened steel, please dont use any of the power saws. You will ruin their blades.
You can buy tungsten carbide hacksaw blades or you could use a ferrous cut off grinding wheel.
If you don’t know the hardness of a metal you want to cut, you should always test it by trying to cut it with a file. If the file just slides over without cutting, your metal is too hard for any toothed blade, and tool steel lathe/milling cutters.
Plasma cutter. Only way to be sure. 
I wound up buying a 6" cutoff saw from Harbor Freight and using that with an abrasive disc. It took quite a while to make the 6 cuts even with that (like 10 minutes per cut). I had a feeling that the rods were too hard to use on either bandsaw, and after how long it took to do with the abrasive disc I’m sure of it.
I don’t really have any other immediate use for this cutoff saw, and I’m willing to donate it to metal shop if they want it. This is the model:
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.
Hasbridge, when I first joined a few months ago, there was a 10" metal cut-off saw in the metal shop (bigger version of what you bought.) Co-chair of metal shop made the command decision to get rid of it - because of misuse. Someone (not the only one, I’m sure) blew up a wheel. Typically, casual users will not ease the blade into the cut and these thin wheels then disintegrate. I expect he or she had to go home and change their underwear - it makes a hell of a noise, not to mention flying shards of abrasive disk I would recommend you leave the little one at home.
Wow do they have no instinct for self-preservation? Did they think it would cut like a piece of wood in a chopsaw.
One of our jewelry saws might work. They are in the black tool box between Vector and Foundry, I’ll be up there Thursday night, 6:30 to about 9 if you need help!