Being the hack that i am, i have broken more than my share of drills and taps and have become fairly proficient at removing them. However this one has me stumped and im about to tap out and send it out to the EDM.
I managed to break a hss Cobalt thread former (actually 2) in some fairly deep holes. What was surprising to me was that the tap shattered like more like carbide at the top of the shank. I was unable to back them out, i couldnt get anything with enough friction to spin them out so i seeing how brittle it was i went to work with a chisel and actually made some progress, more or less prepping it for a faster edm. I had some extra time so i decided to try and drill it out, they are through holes and i have access to the other side, so i was like well if i get really lucky i can back it out or just chew my way all the way back through it. I had some decent shape carbide end mills and drills, the drill dulled almost instantly but it was pretty ready for sharpening already, the end mill was basically new and sharp and made maybe .030 of progress before it refused to go any farther, it was still decently sharp, but refused to cut, it just skated across the surface like i was running in reverse, never seen anything like that before. Just checking to see any suggestions. Ill get a couple more pics in the morning.
I managed to break a hss Cobalt thread former (actually 2) in some fairly deep holes. What was surprising to me was that the tap shattered like more like carbide at the top of the shank. I was unable to back them out, i couldnt get anything with enough friction to spin them out so i seeing how brittle it was i went to work with a chisel and actually made some progress, more or less prepping it for a faster edm. I had some extra time so i decided to try and drill it out, they are through holes and i have access to the other side, so i was like well if i get really lucky i can back it out or just chew my way all the way back through it. I had some decent shape carbide end mills and drills, the drill dulled almost instantly but it was pretty ready for sharpening already, the end mill was basically new and sharp and made maybe .030 of progress before it refused to go any farther, it was still decently sharp, but refused to cut, it just skated across the surface like i was running in reverse, never seen anything like that before. Just checking to see any suggestions. Ill get a couple more pics in the morning.