Originally Posted by OMJ
1" conduit punch makes a 1-11/32" hole. Close but still bigger than 1.25".
For what it's worth, I did a wet test using a hole cut with one if these 1" NPT punches and it will seal properly with the stock rubber gasket that comes with the heater element inside the kettle, but NOT with the method Kal uses.
I'm not sure how food safe that gasket is, but it must be temperature rated, and it does seal.