I just talked to the waterjet guy here.....we have actually cut 14" thick aluminum. Had to make a fixture so the part would actually sit down inside the tank. Very slow tho....like less than 1ipm. Biggest pain in the ass bout the machine is even tho it has a garnet reclaimer....it don't work worth a shit. So every couple of months the machine is down while a couple of part timers get to climb in the tank and shovel all the sand out. Its a pretty big tank too....like 10' by
20' by 3 ft deep. Used to have a mountain of sand out back...the shit builds up after a few years. The city wound up taking it to use for fill on some road project.