Originally Posted by Brulosopher
Great info, thanks! Is there a difference between a conduit and chassis punch? If so which one would I use for the element hole, and what size?
Conduit punches are based on conduit size which isn't the actual size. For example, a 1/2" conduit punch doesn't make a 1/2" diameter hole, it actually makes a 0.622" hole. See:
Chassis (sometimes called 'radio') punches make holes the size that they are rated to be. In other words, a 1/2" chassis punch makes a 1/2" diameter hole.
Most elements require a 1-1/4" diameter hole. So a 1-1/4" chassis/radio punch would be the right size.
Pictures and more information here in the "STEP 4: Punch a hole in the kettle" of my "Heating Elements" article: