13-03-2022, 06:33 PM
You need to make any drill cut not rub. Rubbing greats the heat and takes the edge off the drill. Goinig in with a smaller pilot hole helps as does relieving the drill point. Good quality cutting oil is a must as well. The force required to make much above a standard 5mm diameter drill cut its own hole in a bit of 316 will be on the limit of pressure you can apply with a hand drill.