360 partially rounded head bolt help

Always use a 6 if you can. 12 point still only grabs 6 nut points and at an area about half of what a 6 point grabs at They sell those gouging sockets that literally screw onto the head with a left hand threading. The tighter the bolt, the harder the thing bites. Might bust the head off but then you can pull head over stub and hit it with a torch to break seize. Better question is why is it seized? They dont bottom out if its the correct bolt/head.