I can't figure out why...........

[COBALT]

Originally posted by polevault1977
Broke EZ outs are a pain in the arss. Heat from a torch is a good thing here. Can change the temper esp on the bolt. I work in a machine shop and someone is always bringing a problem like this in. We usually have the luxuary of being able to put the part in a mill vise. I realize you don't have this option. I usually can mill through the ez out with a smaller carbide endmill. You can buy a carbide tipped drill and try to drill it out. They are fairly expensive though. They are super easy to break if you are not use to using them. Might give it a try though. Remember, slow rpm and very light pressure.

One other trick to getting broken bolts out of blind holes. Always drill the hole for the EZ out all the way through the bolt. Not just deep enough for the EZ out. Not exactly sure of all the dynamics, but it works better ever time. Old machinist showed me this one.

Danny

Oh yeah always start with a left hand drill bit if you got one!

That's why I suggested just pulling the head and taking it to a machine shop. They'd have it out in a couple of minutes, but it'll cost you, plus you have to pull the head, which is a lot of work.

The reason drilling through the whole bolt works better is that it weakens the stress the bolt is placing on the threads inside the hole. The way the bolts are made having a void in the center will literally make the bolt smaller - even by a TINY amount.

The problem with this is if the hole doesn't go all the way through. You don't want to end up drilling into the head.