"I've noticed that the threads and back bearing on the collets are being damaged and have to be replaced. What's wrong?"
"Vises, Vise-Grips and pump pliers are the cause of your problem. Purchase several Collet wrenches for each style collet in your shop (5C, 16C, 20C, etc.). This wrench is keyed and locates over the back bearing of the collet to hold it while the threaded stop, Dead-Length assembly, etc. are being tightened into the collet."