Originally Posted by
grizzly59
Soak overnight in penetrating oil, and try drilling with a left handed drill bit. It will tend to back the broken piece out as you drill through. Bit size small enough not to touch the threads of the frame. Usually a well stocked old-fashioned hardware store will have them.
Bingo!!!! I have had a lot of experience removing broken off bolts. The first thing I always did was soak the broken bolt with light oil and let it sit.
Then use a punch to "unload" the bolt, by tapping it down in the threads. Then it looks to me that at this point that an "easyout" bit will get the broke bolt out.