I broke a tap off in a hole I was chasing. The angle got a little tweaked and it snapped below the top of the hole. Its hardened steel. Can I drill it out? Am I screwed?

 

can you reach it with some needle nose pliers to twist it? if not, try using a sharpened punch and hammer to lightly tap one of the flutes, reversing the tap out of the hole. if that doesn't work, your best bet is to take it to a shop to have it edm'd out. (electrical discharge machining). basically burns it out with no damage to the threads... but that can cost upwards of $50-$75.

 

its below the surface of the hole so I can't get anything on it to twist it. Ive tried hammering on the flutes with an awl, which did nothing but mutilate it.

Can I drill this out with a special drill bit? I have a friend with a drill press. I dont really care about the threads they were screwed up anyways, I can helicoil if ness.

Im saving the EDM option for last.

 

try a carbide ball nose endmill, run it slow and use cutting oil. if you have to buy an endmill, it is going to cost you $25-$50 anyway, so you might as well take it to a shop.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Can I drill this out with a special drill bit? I have a friend with a drill press. I dont really care about the threads they were screwed up anyways, I can helicoil if ness. </TD></TR></TABLE>


You'll be lucky not to scrap the part let alone put in a helicoil. We use to try everything to get taps out; drill, machine, waterjet, burn, ect and nothing really works. The only thing I never tried was an EDM, so maybe that would work.

 

There is a part you can get called a tap extractor. They are made by walton, The work good if the tap is not to jammed up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EGJDM &raquo;</TD></TR><TR><TD CLASS="quote">There is a part you can get called a tap extractor. They are made by walton, The work good if the tap is not to jammed up.</TD></TR></TABLE>
yes. those are great.

 

Im looking for a local shop with an EDM machine.

Do you guys think cobalt drill bits could drill hardened steel? Its designed for SS...

 

cobalt won't work very well. you need carbide if you go the drill route.

 

Cobalt is softer than the tap (afaik)...and it wont work too well. x2 on the carbide drill bit.

 

http://www.electroarc.com

 

if it is in steel/stainless, i usually, just take a sharp chisel and break them in to little pieces. just take your time. if its aluminium, good luck.

 

Ok update. The Cobalt drill bits didnt touch it. But I tried a set of double cut carbide burrs that I had and they chewed it up good. But I mutilated the hole so I had to drill it bigger and retap 1 size bigger. (was even too big too helicoil)