I need to mill out the webbing on a flywheel made from round stock, gray cast iron (class 40). I have a bench mill (PM727V with 1KW DC motor) that can do 2000 RPM. The webbing is 0.300" thick. I was thinking of getting a 5/16" carbide endmill and looking for suggestions. the 5/16" was chosen due to fillets in the webbing.