What would be the best way to machine cut a 4” hole in 3/4” stainless? Plasma is not an option. I’ve cut two holes with 3/8 end mill on rotary table but taking to long. I have a Val Cut but it’s breaking bits. I’ve read about a Holex brand with two cutters, they are pricey. Has anyone used the Holex on stainless? Any other recommendations on cutting this part?