I’m also looking at some options for an emergency stop button. Is there an electrical rating on these contacts, like 600V/10A? If so, if you have a 30A power supply, it might be better to put it on the high voltage side.
Are there two contactors on this switch, and are they both normally closed or normally open, or one of each? I would like to kill both the controller and the tool with one button so two normally closed switches would be nice.