Broken Tap HELP!!!

Fish30114

Fish30114

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Jan 5, 2014
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I was tapping a 1/4x20 hole in some 1/4" steel plate to put an aluminum plate on top of it, and the tap broke just as I was turning it through the bottom of the plate. The first hole I tapped went without incident and I felt good about the second hole, but alas--so I am looking for advice on how to get the broken piece of tap out of the steel plate--a small piece broke in the aluminum top plate, but I was able to drive that piece of tap out. I've put a punch and hammered on it, and it doesn't want to move at all. I am open to any advice experience on the issue.

Thanks for any help--Don
 
There are broken tap removal tools available. They have fingers that fit in the flutes.
Commercially they burn the broken tap out with a liquid cooled Electro Discharge Machine. For the cost of a set up and burn, you could probably buy a couple new pieces of steel.
 
How I use to do it was a used up carbide endmill. Run it balls to the walls and plunge it through the middle of the tap. Make sure the endmill is smaller then your aluminum threads or you will remove thoes as well. If the endmill is to large in diamater you can grind the OD smaller on a diamond wheel. Just make shure the grinding tapers smaller as it goes back so the tip of the endmill is slightly larger.
 
Thanks men, that sounds like a way to try JT, I happen to have an end mill or two.

Thanks-Don
 
Sometimes if you're lucky you can spin them out with a spring loaded center punch.
 
I have removed some dang small busted off taps using the endmill trick. But it destroyies the endmill and just be carful so you don't bust that off in the hole. Don't use coolant as it can fracture the endmill. I busted a tap off in the side of a glock I was milling out a pocket on for an optic. After the first cuss words you grab a used warn out mill and remove the tiny tap. If you do it just right you remove the center of the tap and use a small pick and pick the teath of the tap out of the threads.
 
You could TIG weld a piece of stainless to it using 309 rod if it is HSS. Just use some kroil and try to work it out slowly.
 
If you're tapping plate, the odds are there is a piece sticking out of the plate.

grab a hold with vise grips and turn it out.



It would have been nice to do that before you started whacking on it.
 
I really hate to ask, but you were punching from the bottom (tapered end) up, right? :D

Normally they pop out with a good whack. Try hitting it with a torch for a bit.

You may be able to chase a good enough thread after.
 
Thanks for the additional info folks, I think I'm gonna try the torch a bit--and yes Andrew, I was trying to drive it out from the bottom up. Unfortunately there weren't any pieces to grab ahold of Count--it broke clean through about 1/4 of the way down in the hole. What are taps generally made of-HSS? this one looks like it was cast from something, it was a Bosch black oxide tap.
 
Fish30114 said:
Thanks for the additional info folks, I think I'm gonna try the torch a bit--and yes Andrew, I was trying to drive it out from the bottom up. Unfortunately there weren't any pieces to grab ahold of Count--it broke clean through about 1/4 of the way down in the hole.

What are taps generally made of-HSS? this one looks like it was cast from something, it was a Bosch black oxide tap.
Click to expand...

They should be HSS

But is this what you have ?

https://www.boschtools.com/ca/en/bo...-tap-and-die-sets-b44713-2610941901--33155-p/

It lists as high carbon steel.
HSS has been in use for fifty years plus, the only reason for high carbon steel is to make that set cheap and sell it to you at max profit
All those crap taps should be crammed up the nose of the store wholesale buyers that fill hardware stores full of that junk



A tip for you and anyone reading later

The tap and die sets in hardware stores are crap

They are full of sizes you will never use and the quality is crap
The sets are full of hand taps, which come in three styles
Taper, plug and bottoming

You want a taper tap to start a new thread in a new hole
But the indidudual hardware store taps and the sets are ALWAYS the middle tap style a plug tap, which makes it much much harder to turn and results in breakage.


Go to an industrial machining supplier and buy a good quality HSS Spiral Point Tap in the size you need
Not a "hand tap"


If you have no one locally
McNaster Carr
MSC
Enco
KBC Tools
Travers
Sowa Tools

The $4 for the tap you need.


I find it hard to break a 1/4" 20 tap
I can power tap in the drill press with the same tap again and again.



Ive written about this before, try and search for similar posts I've done and you might get photos of the taps and more detail
 
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Drive it out the way it was going in.

In a case like yours I smack the exposed tip hard with a hammer. This will usually break the teeth. Then take a punch and hit it again. It usually pops right out. If itb resists, I hit it with a small and hot torch flame, then repeat the above.

A little clean out of the hole and threads and a new, well lubed tap will finish the job.
 
Thanks Count and Stacy, yeah Count the link you put is the ones I have--I will start on a replacement quest straight away--I actually thought I was doing good buying Bosch--their tools I have, have been good
ones. I did think about why I couldn't find what they were made out of--really sucks since I bought the set of Imperial and Metric tap and dies----seems like I should just order the ones I need from McMaster Carr--I did finally get the tap to break this afternoon, so now I have to get a new tap and see what I can get done--can you get a decent one off tap at Home Depot Count?
 
when i was building my grinder i broke a couple taps in blind bore holes....I just ended up leaving it there and drilling new holes in different spot...not pretty but its a last resort kinda thing if you cant get it out.
 
Lieblad said:
Mr. Bosch would really be cheesed if he knew what his name is attached to nowdays.
In all fairness lots of Bosch products are excellent, alot of it is not.

Anyway, those cheap taps are essentially highcarbon forgings, then points sharpened up via grinding.
Aside from low durability, low accuracy as well.
Click to expand...


Well said Lie, well said.
 
I've always been able to get my broken taps out, by hammering at different angles with a punch. Usually you can get it to shatter.

And yeah, those "Carbon Steel" taps are junk. HSS is the way to go! To anyone that thinks bad about HSS, try buying some Norseman Black and Gold HSS drill bits - those things are fantastic!
 
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