I constantly have to drill 3 inch holes in 1/8 inch thick stainless steel. I currently use a high power corded drill and a 3" bi metal hole saw, drilling slowly and applying cutting oil as needed... It takes a really long time, I go through tonnes of hole saws, and it's really aggravating. Does anyone know of a better tool for the job?

You could easily make yourself up a press which would be the cheapest option, or if you have money to burn a plasma laser and computorized set up the you can just leace it to the job

I agree with Peter, a plasma cutter or a 3 inch die used in a hydraulic press would simplify the process.