Yes i presume they are for bending pipe not tubing, and they are just going to kink the thinner staff, but i have a project coming up that they should come in helpful as i'll be using thick wall tubing.
I have found adding a shim to the die if it's close to the size you need helps. I've also capped the ends of the tube after I filled the tube with sand for thinner stuff. You can do a lot with the "kinker".