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Way to remove broken tap

machinist man

Aluminum
Joined
Apr 16, 2008
Location
Northern Minnesota
I don't know if anyone has tried this or not, but it worked for me. I had a part I was working on this week that had some 6-32 tapped holes in it. Everything went good until I broke a tap off. I've used carbide ball nose endmills to drill out a broken tap, but I didn't have one small enough. Then, I thought I would try a carbide burr. Worked like a charm! Ran it about 3000 rpm, plunged it down .001 at a time, and I had it drilled through the tap (about 3/8 long) in a few minutes.
 
Sounds like a good idea, uh if I was ever to break a tap. I usually use the Omega Drill, but centering is the problem because they're never broken off flat. This way you could more easily get on center it would seem. Thanks!

Ray
 
I had a run of 6/32 taps break on me a few years back when I was working outside the home. The taps were sharp and new and I couldn't figure out what I was doing wrong..until I saw something that I never witnessed before.

The maintenance man was coming into the shop at night to use the machines to do "home work". He was using the 6/32 taps as "great little centerpunches."

I guess a whack or two would fracture the tap enough that it would fail when under maximum load. He got his ass chewed out and lost his keys to the shop, we got to clean our own shop and I got to learn the fine art of removing fairly small taps by using a liberal amount of Kroil and a pair of jewelers needle nose pliers. Just squirt, warm a bit then grab the tap in the flutes with the jewelers pliers. Work it back and forth until you can get a quarter turn room, then work out slowly.

Jewelers needle nose are made small enough to take out a 4/40 tap.
 
I tried weldind on a nut to a 1/4"x20 broke tap. The welding made the tap so brittle
I broke the nut off by hand and the welded portion of the tap was like metal dust.
 
...I had a run of 6/32 taps break on me a few years back ...The taps were sharp and new and I couldn't figure out what I was doing wrong..until I saw something that I never witnessed before.

The maintenance man was coming into the shop at night to use the machines to do "home work". He was using the 6/32 taps as "great little centerpunches."

I guess a whack or two would fracture the tap enough that it would fail when under maximum load. ...

I had one break on me recently after I dropped it on the concrete floor. The tap looked fine so I went ahead and used it, but the fall had apparently damaged it and it snapped with very little torque applied.

Cal
 
Hey Fluted, where can I buy a set of those pliers ??

I bought mine about 10 years ago from a hobby company in NY. They are a box jaw configuration, which makes them VERY strong for their size, especially when it comes to the twisting motion needed to remove taps. I paid (then) about $20 each plier, and I have two. One has longer thinner tips than the other.

Brownells sells pliers LIKE them, but from the pics they seem proportionally larger. You could look up "jewelers supplies" on the net or talk to a friendly neighborhood jeweler if you can find one. The pliers that I bought were used to make small rings of gold when you finish off a bracelet or necklace (to give you an idea of their size).

Mine are scarred up from much use, but the joint is still tight. I can find no manufacturers mark on mine any longer, but IIRC, they were made in Germany. Even at $30 each they would be worth the money for how well they work.
 
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The 6-32 I removed was 2-3 threads down. I use a big cup with a gas lens, .040 tungsten and .025 dia 304 filler rod. reach down the hole and build up the tap till it is a bit proud of the surface then weld a nut or bolt on and back the tap out. no problem.
 
I use the same procedure as moonlight, but I usually just build up the weld where I can grab it with a Vise-Grip. Works great on broken studs also. If I need more torque I will put a nut over the projection and weld it on from the top. Saves trying to figure how to hold the bolt while welding it to the tap.
 
I have had my share of HSS taps that break. No more.

High performance Greenfield taps are the way to go for me.
Never had one break. Store them in Altoids boxes.
 
.until I saw something that I never witnessed before.

The maintenance man was coming into the shop at night to use the machines to do "home work". He was using the 6/32 taps as "great little centerpunches."

The first and only time I saw that was an installer Anilam flew up from Florida to install a DRO on a new engine lathe for me. He didn't have a centerpunch with him so he used a 3/8-16 tap for a centerpunch. Boy was I impressed.
 
67Cuda, My customer did not have that luxury....... It was a big money, very complicated part that was due in a day or so. It was fun to remove it so easily while the customer waited. He was impressed and I think He will be back.
 
I too have had luck removing taps from parts over the years.

It takes a good pair of hands to do this well and consistently.

There are only a few individuals in the shop that are trusted to not make the mess worse.

After a short while you will have a selection of tools to help rescue the part.

These include Dental picks, (Beg some from your Dentist, You Won't be sorry)
After awhile you will have quite a collection. Assorted small pliers and Vise Grips.
Assorted Tap Removing Sets with the 3 and 4 Fingers.
Plus other tools for larger sizes.

I have had luck removing 0-80 up to 1/4-20. Any Larger and they go to the EDM or Bridgeport's for removal.

Nice tips in this thread.

Thanks

Mohawk
 
I don't know if anyone has tried this or not, but it worked for me. I had a part I was working on this week that had some 6-32 tapped holes in it. Everything went good until I broke a tap off. I've used carbide ball nose endmills to drill out a broken tap, but I didn't have one small enough. Then, I thought I would try a carbide burr. Worked like a charm! Ran it about 3000 rpm, plunged it down .001 at a time, and I had it drilled through the tap (about 3/8 long) in a few minutes.

Like many others here have said there are several methods that can work and it takes some expeirance to deturmin what will work best in each indivual case. Here's the order I try to remove taps in.

First see if you can use a Waldon tap removal tool. You need the right number of fingers for the number of flutes on the tap and the don't work on spiral flute taps.

Next comes the picks and pliers or whatever you can get a hold of the tap with.

Third would be to machine the tap somewhat inside of the flutes. This allows you to calpse the tap or break it up to get it out of there. For this I use solid carbide, strait flute, 135 deg. point drills. These are sold by Ford Tool as "High-Rock" drills and other companys call them "Rock-50" drills. These are meant to drill hardened steel and will cut a tap well. Run them fast (like 2500 RPM if you can get it) and don't use any coolant, but I keep an air hose blast on the tap while. You may need to flatten the broken tap end with an old endmill or a dumore style grinder to get a flat to start the drill.

If these fail it's edm/tap burner time.
 
Boy, it's good to see so many methods here. The more you know, the better chance you'll get those little buggers out! I've used a ball nose endmill before, like I said before, the only problem is that it usually trashes the endmill.
 
I don't know if anyone has tried this or not, but it worked for me. I had a part I was working on this week that had some 6-32 tapped holes in it. Everything went good until I broke a tap off. I've used carbide ball nose endmills to drill out a broken tap, but I didn't have one small enough. Then, I thought I would try a carbide burr. Worked like a charm! Ran it about 3000 rpm, plunged it down .001 at a time, and I had it drilled through the tap (about 3/8 long) in a few minutes.

Well, you inspired me to fix the 1/4-20 hole on the back of my Unisaw which
holds a Biesemeyer fence. I bought a 1/8x1/8 carbide endmill and a helicoil
insert. Got home and realized I didn't have the 5/16-20 tap for the helicoil
so I did something different.

1. cleaned out the broken tap from the hole with the endmill attached to a Dremel tool.
(The tap was HSS and broke because it was the only blind hole out of the 15 that had been drilled in the table to hold the front and back rails).
2. enlarged the hole with 17/64 drill and tapped with a 5/16-18 tap.
3. Got a 5/16-18 stainless bolt and cut off about .600 of the thread.
4. drilled a #7 hole into the center of the .600 thread piece. Finished offboth ends.
5. applied J-B Weld to the hole and the .600 piece and screwed it in flush.
6. wait 15 hours and tapped the inside of the .600 piece with a 1/4-20 tap.

One of the reasons I like Powermatic Saws is that they are sold with Biesemeyers installed.
 








 
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