I bought a set of hole saws from harbor freight to cut the ends of tubing and pipe and this works well so far....I use my drill press..................I see this trick on youtube..............

I bought a harbor freight fountain pump 10.00 and have cutting fluid pumping from a turkey roaster up and onto my spinning holesaw to keep it cool and so it does not lose it's temper and hardness and get dull....

the fluid falls back down into the roaster pan and this seems to work good for me........the tubes are notched really nice this way.......................