So I was cleaning up threads and retapping a hole on this housing and the ------- tap broke off below the surface.

Drill out like a normal broken bolt? what kind of bit?

 

drilling it would be a bitch for a few reasons, its wierdly shaped and made of hard *** steel... can you fit a piece of metal in two opposing "holes" and then use a longer bar to turn the tap out? or weld something to the tap... that could be tricky.. but probably not bad if you have a mig...

 

hmmmm weld something to it....possibly....ill get back to you

 

thats some ---- luck right there

 

nah not going to happen, broke off to low below the surface, i tried tried also to use a dremmel to saw a little slot in it, and then use a hammer-driver on it but that ----'s not happening either

 

get some needle nose plyers and grind them down so you can fit the ends into the "hollow" spots of the tap. Try heating up the housing, PB all to hell and see what happens.

 

They make tap extractors that is an assebly of little bars that fit in between the flutes of the tap so you can turn it out, but they never worked for me

It is hardened steel so you will not be able to drill it, but I have had some luck shattering them out.

Usually I just try to shatter it and drive it through, then run another tap through to clean it up. If there are no threads left I go a size bigger or use Heli-coils

 

you can try those easy out bits but i probably wont work for your situation

 

haha. That won't work.


Try a tap extractor, or needle nose pliers, like stenseltizm suggested. Your tap was most likely mad out of High Speed Steel. Drilling that will not exactly be easy, even with a carbide drill.

My machine tools book mentions using an acid, to east away at the material being tapped, around the teeth of the tap. This will "loosen" the tap allowing it to be freed. Never tried or seen it though.

 

Just had to deal with the same thing in a my wastgate flange. I tried all that was mentioned above except the acid, none worked. Ended up using a punch and a 2# hammer. Then drilled it out and just used a bolt and nut, but a heli coil would work also.