Broken tap troubles?

Question

I thought a bolt was broken off in a bolt hole, - I got a brand new cobalt split point drill and used lots of pressure but the bit just sits and spins in the (old) depression on what I thought was a snapped off bolt. It is on a tractor (rebuilding) so I cannot haul it into a machine shop.

What next? - Any ideas on how to drill through or remove a broken off tap, - hole is about 7/16".

Thanks Bob Durango

xxxxxxxxxxxx I do hope this is not a repeat posting, - I tried sending this by mail and think I just figured out how to start a post. I regret it if I posted doubly. xxxxxxxxxxxxxx

JR North · Accepted Answer

7/16 is just about big enough to get a small needle nose plier in to turn out the tap by the flute webs. Unless, of course, some nitwit really seized it. 7/16 is also big enough to get a #1 cutting torch into to burn down the webs. Been there, done that. If it is broken above the shank/flute junction, you can still burn it out with a blue wrench and then do the above. If it is a tap, that is....JRDweller in the cellarBob wrote:

Glenn · Answer

I have had fair success in removing taps by just hitting them with a punch.  They tend to shatter fairly easily and then you just pick out the pieces and  clean up the threads. Or burn it out with a carcon arc rod or a blue tip wrench. Glenn

Bob · Answer

xxxxxxxxxxxx What is a blue tip wrench? Bob

Snag · Answer

AKA oxyacetylene cutting torch .

RoyJ · Answer

Works quite well on high carbon taps stuck in cast iron. But it is not for the shaky of hand or faint of heart. Takes 30 seconds and you are done. Best if you can find someone who has done it before.Snag wrote:

Tony · Answer

Die grinder (air or electric) and a carbide burr. Even a dremel would work.If you damage the threads accidentally you can always helicoil.Tony

oldjag · Answer

Try laying a nut over the broken tap/bolt and TIG weld thru the centerof the nut to the broken bolt or tap with filler rod.  Then justunscrew the nut and bolt together.  I have had great success with thismethod, especially on cast iron parts.  The localized heat from the tigreally seems to help break the bond between the bolt/tap and the work.The iron is protected from damage from the arc by the nut.  Just didtwo Audi Quattro iron spindle bearing hubs this way.  They had 250Kmiles of use in the salt belt, and the bolt head were rusted round.Pulled 6 bolts in total with no damage to either hub or the backingplates they were holding.

Bob · Answer

Thanks! - Very clever!

Gunner · Answer

Also known as a Fire Axe

Folks? Other common names?

Gunner

"If I'm going to reach out to the the Democrats then I need a third hand.There's no way I'm letting go of my wallet or my gun while they're around."

"Democrat. In the dictionary it's right after demobilize and right before demode` (out of fashion).

-Buddy Jordan 2001

Grant Erwin · Answer

>AKA oxyacetylene cutting torch HEAT WRENCH

Randy Replogle · Answer

Do you use a nut with a hole smaller than the tap diameter to avoid welding the tap to the piece it's stuck into?Randy

Broken tap troubles?

Join the Discussion

Didn't find your answer?