removing broken taps from attempting to thread SS with M8?

[Daydream believer]

Last one I broke I removed by using a security headed hexagon piece rather like a philips screwdriver tip but one with 2 pins for security screws. insert bit
The 2 pins went in down past 2 of the 3 sides of the broken tap & was enough to turn it

 

[vas]

thanks for all the info guys!

well since the tap didn't break within an expensive machinery but rather a plain piece of rod, just scrapped that bit and went further, just did hole and tap #2 and 3, must have done something better than the first time as there was no drama and finished with both holes and taps within 5mins. Obvs hole one had hardened the steel , maybe because it was too close to another hole that was done with a blunt drill and took ages. Anyway, getting better at it.
For the record the tap is a Volker (o with umlaut or whatever you call that fancy two dots on top...)

Off to the boatyard to fit them in the morning, then back at noon to do the other side taps.

For the record the broken protruding bit was a few mil on the one of the three cutting sides, the other two where inside the hole, no chance of welding something there I'm afraid.

cheers

V.

 

[burgundyben]

Remember Vas, if at first you dont succeed, destroy all evidence of having tried.

 

[vas]

Remember Vas, if at first you dont succeed, destroy all evidence of having tried.

correct Ben, offensive piece circa 100mm long on scrap bin in the boatyard, all clean

 

[reeac]

Just wondering if thermal expansion/ contraction would help. 304 SS is 17.3x E-6/degree C whereas a tool steel is 10xE-6/degreeC.. Heating would therefore expand the SS bar more than the tap and might just loosen it a bit.