Unless the threads are stripped, all you really need to do is dress the tips of the thumb screw. This applies to all of the EX type saws including DeWALT, the newer Deltas, king and even the Pegas. Take a 3 or 4” square piece of hardwood or BB. Drill a hole with a drill press in the center. Use a bit slightly smaller than the threads of the thumb screw. Screw the thumb screw into the hole making sure it screws straight into the jig till it just barely protrudes out the bottom. Then, rub it on some 220 grit sand paper till the tip is no longer shiny. This should be a routine maintenance thing to do. I do this every two to three weeks without any degradation to the thumb screw.