I need to clamp a round piece of tubing into a chop saw--and I need to clamp it on both sides of the chop saw blade. (Clamping something round doesn't work very well, of course.) My plan is to make two squares with a hole cut through each of the correct diameter. There will be a threaded hole at the top of each square into which a bolt will go that will lock onto the tube to prevent it from rotating. I will machine these rather precisely.
But before I make these to fit 2" and 2.75" tube diameters--is there anything like this whose name I do not know, and that is why I can't find it? I would think the need to hold a round piece in position on a chop saw would be pretty common.
UPDATE: I was thinking about this, and I see a way to make something like very easily. Buy square aluminum tube where the inside dimensions are the same nominal diameter as the tubing, and the wall is perhaps 1/4" thick. The inside dimensions of square tubing are typically slightly smaller than the nominal outside diameter of the round tubing, so I can mount the square tube in my 4-jaw chuck, and use a boring bit to enlarge a few thousandths of an inch so that the round tube goes into the square tube. Then cut the square tube into the two sections, and drill and tap a hole for the bolt that locks the round tubing in place. Now I have something that locks the round tubing in place, and that will allow me to use the work clamp on the chop saw to hold everything in place.