Broken Tap

[palacio]

Any advise on how to remove a broken tap on a 304 stainless steel ?

[Osprey Guy]

I've never had the need to try it myself...but I understand that you can remove the tap by letting the piece soak overnight in ferric chloride. The (mild) acid won't bother the stainless steel...but will eat away at the tap to the point where it's easy to remove.


Dennis Greenbaum

[tmickley]

I've soaked a broken tap in acid in Ti but not stainless. The acid soak works quite well. I'd test that first on stainless.
Normally, you try and grab the broken piece of a tap somehow and turn it back out but I'm sure you've tried that along with some colorful language. If it's a through hole, try smacking the tap fragment with a pointed punch and shattering the tap to pieces. You may have to go up a size due to hole deformaty. If it is a blind hole, that won't work. If you have carbide bits you can try drilling it out but carbide bits are usually more expensive than the part and tap combined and this kind of treatment can chip one pretty badly. Good luck. Broken taps suck, that's all there is to it...

[palacio]

How about Nitric acid ? will that work too ?

[jwfilion]

In the machine shop I worked in, we used to use carbide burrs in small air (pencil) grinders, depending on the size of the tap and the depth. We slowly ran the burr back and forth along the flutes until the tap broke. Tap is easier to remove if in pieces. Easier job if it's a through hole as well. We only did this if the job was worth the cost of broken burrs. No EDM in that shop. Of course, I've never had to do this myself, as I have never broken a tap.

[HAKViking]

Hi palacio,

This document can give you some ideas: http://www.metalartspress.com/PDFs/R..._Fasteners.pdf

I wouldn't use ferric chloride. I have used it for marking stainless steel in the past and it etch SS easiely.

Regards,

HV