I've been working on the car for about two months now. Used a DA Electric Mill. Wanted to go from 5" to 6". Choose this pneumatic device. Immediately after unpacking, the cover screw is bent. Even the slightest deviation will cause the entire tool to vibrate in your hand and you will not be able to control it and you will end up with smooth sand. It's not as powerful as the electric version. This surprises me as I have been using pneumatic tools for many years. I have a 220 amp industrial size air compressor at the shop so this is definitely not a problem. I have requested a replacement and will update this once I receive it. But Porter's corded DA electric grinder seems to have more power.