Author Topic: tap extraction  (Read 1538 times)

Offline thecapgunkid

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tap extraction
« on: August 25, 2023, 11:26:12 PM »
8X32 waited to break just as the head was reaching the other side.

..." Easy...easy...don't break it...Back Off! Try again.   @#$%^&!!!!"

How do I get it out?

Thanks

Capgun

Offline PhDBrewer

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Re: tap extraction
« Reply #1 on: August 26, 2023, 12:19:51 AM »
Many ways...
Soft screw? Drill a small hole, use center punch first, and use an "easy out".. which are not very easy. Left hand drill bits are handy for this cause sometimes the screw backs out while being drilled.
Or if harden screw or the tap itself, I freeze with a freezing liquid in a can. Then snap pieces off with a punch hitting towards the center. Always work in a direction away from the threads to protect them.
Hope this helps!

William

Offline HSmithTX

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Re: tap extraction
« Reply #2 on: August 26, 2023, 12:24:34 AM »
The best way is to grind the center out and then the flutes will fall out of the hole,  a pencil grinder and a carbide or diamond burr will do fine. It's the only way I have ever seen that doesn't damage the hole and threads in the hole,  load a new tap and lube and finish the tapping.  I have done this as small as 4-40 under magnification.  You might get lucky with one of the tap extractors and not wreck the piece you were tapping but odds are against it,  if the tap was shallow enough and it was a plug tap there might be enough metal left in the hole to get a quality thread after using a tap extractor.  If you know someone that works in a machine shop with a hole popper they work fantastically as well, EDM the center out of the tap and the flutes will fall out of the hole that way too. 

Offline Bob Roller

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Re: tap extraction
« Reply #3 on: August 26, 2023, 12:57:25 AM »
What size drill were you using for the 8x32 tap? I think a #29 is the recommended size.countersink the hole on both ends the depth of one thread and be sure to use a threading fluid.High speed taps also instead of the carbon steel ones from a hardware store.Getting a broken one out is sometimes a hopeless case so good luck with that.
Bob Roller

Offline Angus

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Re: tap extraction
« Reply #4 on: August 26, 2023, 05:11:31 AM »

Tap burner, tap disentegrator, hole popper, whatever term you want to use, this machine does a good job without destroying the part. Some machine shops have them. The shop I work at has one, we call it "Gary". Glad I'm not him.

If the tap has straight flutes and there is a clear passage through, a wire edm can cut it out. The shop I work at has this too, but no personal name.

A mill setup with a small carbide burr or diamond burr.

Offline Sand Watcher

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Re: tap extraction
« Reply #5 on: August 26, 2023, 05:16:30 AM »
There's a guy in Santa Ana who makes a living removing broken taps from machine parts. He has a few good videos about how he does some of them. https://www.youtube.com/@JerrysBrokenTap

Offline bobw

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Re: tap extraction
« Reply #6 on: August 26, 2023, 05:07:36 PM »
If it’s high speed steel a carbide end mill will take it out.  Use one small enough to cut the center out.  Best to find someone with a vertical mill when using carbide, needs to be very rigid.  Carbide sounds good for taps and drills and it is very tough, but also very fragile and does not take unusual or interrupted side loads like you get when using them by hand.

Offline thecapgunkid

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Re: tap extraction
« Reply #7 on: August 26, 2023, 05:13:30 PM »
Thanks.  As I have often stated, there's a reason Cordwainers make shoes and RIFLEMAKERS make rif;es...

Offline Dphariss

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Re: tap extraction
« Reply #8 on: September 15, 2023, 06:22:47 AM »
Like Bobw said. But buy at least two centercutting carbide mills. They break REAL easy. One just a little smaller than tap drill is what you want.
He who dares not offend cannot be honest. Thomas Paine

Offline Pete G.

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Re: tap extraction
« Reply #9 on: September 15, 2023, 10:35:05 PM »
Tap extractor, I got mine from Amazon. You have to specify number of flutes.

Offline Randall Steffy

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Re: tap extraction
« Reply #10 on: September 16, 2023, 12:19:45 AM »
It is likely no consolation, but you have to break numerous taps during your lifetime to really know tapping metal and what they will thread before they break and that a dull tap is a broken tap waiting to happen.

Offline Steeltrap

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Re: tap extraction
« Reply #11 on: September 16, 2023, 02:44:23 PM »
Way back in another lifetime, I worked as a machinist, on a drill press that was likely bigger than most cars. Large overhead crane was used to place & remove the pieces I worked on. And the speed/feed settlings could all be very precise. I also used a tool called “Tap Break” that was essentially a clutch that would break/slip before the tap broke. Tap Breaks were coveted tools & once you had a good one, it went deep into your tool box because if you “shared it” with the other shifts, it would get “lost”. 

When a tap broke it was a “Royal” to use an electronic tap burner, but the tap could be removed without damage to the piece. And….you did not want to damage these large pieces.

Morale of the story is it’s far better to use a new, sharp tap than to attempt cutting with a worn one. Time is money and removing broken taps is not fun at all.