360 partially rounded head bolt help

toolmanmike said
If you can't flag down a tool truck try a parts store for one of these twist sockets. The harder you pull the more they bite. Take a headbolt along to get the correct size. toolman

Those are what the Craftsman extractors are like; they work very well.

My experience was on a head bolt that suffered ALOT of corrosion, no regular socket was gonna get it out.