I am having some tapping problems which is another subject. I now have an M6 tap stuck in a 316 hole, broken off. It isn't that expensive a piece, but I'd like to try to mill the tap out of the hole. I've tried this before and broke the mill off in the tap ;(.
So I'm wondering what the tricks are if any. I can center on the hole as the part is fixtured. I think what happened the last time was the end mill started to break up the 3 flute tap, and the bits jammed the end mill. Tap is HHS. Since the pilot hole is 5mm (but I have no 5mm end mills) I was going to try a 4 flute 3/16 end mill. It seems like there is still the possibility of the tap flutes breaking up as the end mill eats the middle, causing chip jamming and breakage.
What are the secrets to this?
So I'm wondering what the tricks are if any. I can center on the hole as the part is fixtured. I think what happened the last time was the end mill started to break up the 3 flute tap, and the bits jammed the end mill. Tap is HHS. Since the pilot hole is 5mm (but I have no 5mm end mills) I was going to try a 4 flute 3/16 end mill. It seems like there is still the possibility of the tap flutes breaking up as the end mill eats the middle, causing chip jamming and breakage.
What are the secrets to this?