I broke a headbolt in the block while trying to remove it from my friends truck.

Now its coming down to me getting my car running and this bolt is driving me up the wall.

My friend let me borrow a full carbide drill bit but it was too big, I center punched, center drilled, and used the carbide bit to go down a little bit. I bought a carbide tipped drill bit today after getting off work, I used oil and I was going relativly slow.. the carbide basically exploded.

Any tips on what I should be doing?

What kind of drill bit should I be looking to buy? I'm thinking I need a full carbide bit or a tungsteon bit.

This is pretty much the only thing holding me back right now and I really want to resolve this issue. Any help is greatly appreciated.

 

Try a left hand cobalt bit. Be careful not to damage the block.

 

left hand is good, regular old HSS will work just fine