Step 1: Chuck It Up!
In my case, a 7/16-inch socket with a hex base made for hand drills had the perfect exterior diameter for a really tight friction fit with the interior diameter of the tube.
Sorry for the mixed-up photo timeline. I really came up with this quickly and was surprised it worked as well as it did and I didn't think to take pics until well into the project.
Step 2: Start Lathe-ing!
The hacksaw blade's teeth will need to be facing into the feed or rotation direction. The vertical - not angled - face of the teeth should face into the tube material as it is rotating in order to cut.
Start the drill slowly to get a line or indentation that will help "hold" the blade in place on the tube before getting all Western and pulling the trigger fully.
Step 3: Cut.
Step 4: End Result
400-grit wet/dry paper is a project staple at my house, it comes in handy for cleaning and polishing all kinds of stuff.
After buffing the whole thing with steel wool, I used Birchwood-Casey Super Blue Liquid Gun Blue cold-bluing solution to refinish the piece. Looks almost like I know what I'm doing!
The cutting could be done on any type of material too thick or not otherwise meant for a tubing cutter when you need a cut that DOESN'T look like it was done with a hacksaw.
The bluing came out nicely and can be done on ANY nickel and chrome alloy steels, even hardened. So, refurbish your Grandad's (or Grandma's) pocket knife, tools, watch case, etc., etc.