Author Topic: Broken tap.....Finally did it!  (Read 996 times)

Online smallpatch

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Broken tap.....Finally did it!
« on: June 12, 2019, 08:26:00 PM »
Ok, I've been doing this a long time, and today, I finally did it.
No room for a 8/32 lockbolt, so I drilled for a 6/32" was careful tapping, but the hole is right on the edge of the bolster, and snapped it off flush.
As I said, no room for a 8/32, so drilling it out is not an option.
Any advice???
In His grip,

Dane

Offline Dennis Glazener

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Re: Broken tap.....Finally did it!
« Reply #1 on: June 12, 2019, 08:34:37 PM »
Ok, I've been doing this a long time, and today, I finally did it.
No room for a 8/32 lockbolt, so I drilled for a 6/32" was careful tapping, but the hole is right on the edge of the bolster, and snapped it off flush.
As I said, no room for a 8/32, so drilling it out is not an option.
Any advice???
I got one out by using a small screw driver and kept tapping on a flute of the tap until I finally backed it out, I was extremely lucky! If I remember right, its was years ago, I used a Mapp torch to heat the plate/tap before I even tried to tap it loose.
Dennis
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Offline flehto

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Re: Broken tap.....Finally did it!
« Reply #2 on: June 12, 2019, 08:44:29 PM »
Dane....take the lock to a tool shop that has an EDM...most do nowadays.....Fred

Offline Pete G.

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Re: Broken tap.....Finally did it!
« Reply #3 on: June 12, 2019, 08:54:28 PM »
I bought a broken tap removal tool. It has small fingers that engage the flutes of the broken piece and use a wrench to back it right out.

Offline WKevinD

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Re: Broken tap.....Finally did it!
« Reply #4 on: June 12, 2019, 09:20:25 PM »
I did the same thing a while back and I ended up taking it to a machine shop a few miles away. I found a nice guy took it as a challenge and drilled it with a fine bit and smacked it with a punch, it fractured the remnants of the tap and I was able to pick them out with dental tools.
I've switched to different taps (two flute) and have been able to avoid breaking any more (so far).

Kevin
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Online smallpatch

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Re: Broken tap.....Finally did it!
« Reply #5 on: June 12, 2019, 09:22:17 PM »
Ok Dennis,  I guess I'm lucky too!
Couldn't get it to turn because it was catching on the edge of the bolster, so before I bought a new plate, I milled the  bolster down in just that area flush with the back of the lock plate.  One light tap with a punch and it fell out.
Must have just been started in the lock plate.
Thanks all.  Panic is over.
In His grip,

Dane

Offline Bob Roller

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Re: Broken tap.....Finally did it!
« Reply #6 on: June 12, 2019, 09:26:48 PM »
IF it's a "hardware store" tap it probably is carbon steel and not
"High Speed".If it's carbon steel it can be heated red hot with a
small tip torch and cooled slowly in warm sand and then punched out or drilled.
I gave up on these cheap taps and cheap everything else when it comes to tools
of any kind.
Bob Roller

Offline Scota4570

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Re: Broken tap.....Finally did it!
« Reply #7 on: June 12, 2019, 10:22:10 PM »
The only way I have successfully removed high speed tiny taps is to use diamond dental burrs.  Go carefully and stroke the flutes.  You will cut it into little pieces that fall out. 

Other thing is that if tap squeaks I back out immediately.  Then resharpen the tap or toss it.   

Offline Frank

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Re: Broken tap.....Finally did it!
« Reply #8 on: June 12, 2019, 10:27:41 PM »
I always use carbon taps because they can be punched out if I ever snap them off.

Offline DaveM

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Re: Broken tap.....Finally did it!
« Reply #9 on: June 12, 2019, 11:00:40 PM »
The exact same thing just happened to me a couple of weeks ago, also tapping a lock screw.  I struggled searching online for any thing that may work.  Just by luck, experimenting with Dremel bits, I found a method that worked beautifully: 

If you have a Dremel, and a small size white silicon carbide grinding stone for it, I ground through the broken tap by just grinding away straight down on the center flat broken tap.  I think it only took me a few minutes, it practically melted the tap as it went down. It took out the tap and left the threads intact. 

Offline Bob Roller

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Re: Broken tap.....Finally did it!
« Reply #10 on: June 12, 2019, 11:37:50 PM »
That's one of the cheap taps I was talking about.A 6x32 thread is a wretched thing at best and a 6x40 or 48
is better.I don't know if I even have any 6x32 taps or dies now. That 32 thread is too coarse for the .130
diameter tap.

Bob Roller

Online Jim Kibler

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Re: Broken tap.....Finally did it!
« Reply #11 on: June 12, 2019, 11:44:12 PM »
Good quality spiral point gun taps are best for the work we typically do.  I've removed a good number of broken taps, from customers,  by milling them out with a 1/8" carbide endmill.  Hold the plate well and plunge through the center.  It's amazing what good carbide tooling will do. 

Offline smart dog

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Re: Broken tap.....Finally did it!
« Reply #12 on: June 13, 2019, 12:51:44 AM »
Hi Jim,
Thanks for that input.  Could you make a recommendation about manufacturer?  I looked at MSC and there are so many it would be nice to get endorsements. I need to resupply with new taps soon and I would like to follow your advice.  My need is for hand taps, both plug and bottoming.

dave
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Offline Scota4570

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Re: Broken tap.....Finally did it!
« Reply #13 on: June 13, 2019, 03:59:37 AM »
That's one of the cheap taps I was talking about.A 6x32 thread is a wretched thing at best and a 6x40 or 48
is better.I don't know if I even have any 6x32 taps or dies now. That 32 thread is too coarse for the .130
diameter tap.

Bob Roller

Agreed.  6-48 is a standard size for modern guns.  High quality screws are easy to buy from brownells and others.  I have a box of taps, dies, countersinks,  and screws all for 6-48.  I use them whenever practical.  I do not understand why someone would use a #5 screw or an unobtainium metric size when 6-48 will do the same job.  Especially in locks or attaching ribs.  Why not use high quality hardened 6-48s?  Small soft screws made of leaded alloy are a major annoyance. 

Offline Berksrifle

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Re: Broken tap.....Finally did it!
« Reply #14 on: June 13, 2019, 05:23:23 AM »
What Jim Kibler said.

I use a ball carbide end mill. Found out the radius end does not allow the edges to chip or get dull as quick as a flat end mill. Use at high speed.

Ken

Offline FlintFan

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Re: Broken tap.....Finally did it!
« Reply #15 on: June 13, 2019, 02:49:52 PM »
Good quality spiral point gun taps are best for the work we typically do.  I've removed a good number of broken taps, from customers,  by milling them out with a 1/8" carbide endmill.  Hold the plate well and plunge through the center.  It's amazing what good carbide tooling will do.

+1 on this method.  Have removed dozens this way over the years.  Works great.

Only suggestion I might add is to raise the knee up into the cutter, instead of lowering the quill like you would with a drill.  I have found you have a little more control that way, and have less chance of breaking the cutter.

 

Online Jim Kibler

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Re: Broken tap.....Finally did it!
« Reply #16 on: June 13, 2019, 03:45:57 PM »
Hi Jim,
Thanks for that input.  Could you make a recommendation about manufacturer?  I looked at MSC and there are so many it would be nice to get endorsements. I need to resupply with new taps soon and I would like to follow your advice.  My need is for hand taps, both plug and bottoming.

dave

I often buy these from McMaster Carr.  Here's a link to what I use for tapping through holes:  https://www.mcmaster.com/2523a447

These won't work for blind holes very well as they push the chip forward. 

Thanks,
Jim

Offline smart dog

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Re: Broken tap.....Finally did it!
« Reply #17 on: June 13, 2019, 05:26:12 PM »
Thanks Jim!
dave
"Flick Lives!"