Broke a Tap while Threading new hole

pmsmechanic · Jun 27, 2014

I've had good luck with beating the tap out as Tor Arne suggested. I usually just use a helicoil but I have just tapped the resulting hole with a new tap and called it good. I can see welding work also. The only thing I can add is that once your done welding just take some wax and let the heat from the weld melt it into the hole. Wax works awesome as a penetrating fluid.

SPIKER · Jun 27, 2014

10-24 is pretty small for welding nut on unless you have heli-arch/tig welder. so far there are 3 good suggestions I've had some luck with all of those methods.

One thing is to make sure you are using correct size drill bit, make sure you have only slightly more depth of metal than 3 full thread lengths of the size. So for 10-24 tapping more than 1/4" thickness is a waste. if you were tapping a piece of 1/2" plate drill it all way thru and open the hole up halfway with a #21 drill bit in stead of the #25 so that you are not using full length of tap in the tight hole...

930ck · Jun 28, 2014

Was able to drill out a broken tap by heating it up with a torch cherry red so the tap was annealed, let it cool and then drilled it out.

Mendonsy · Jun 28, 2014

SPIKER said:
10-24 is pretty small for welding nut on unless you have heli-arch/tig welder. so far there are 3 good suggestions I've had some luck with all of those methods.

One thing is to make sure you are using correct size drill bit, make sure you have only slightly more depth of metal than 3 full thread lengths of the size. So for 10-24 tapping more than 1/4" thickness is a waste. if you were tapping a piece of 1/2" plate drill it all way thru and open the hole up halfway with a #21 drill bit in stead of the #25 so that you are not using full length of tap in the tight hole...

YEP!! Generally all that you need for thread depth is the diameter of the fastener. Anything more than that is excess.