broken tap

[john hamilton]

OK, now I've done it. Broke off a 5/16" x 18 tap in a piece of 3/8" steel. It's broken off even.
What do I do now? Doesn't look big enough to weld a stud to, or is it?
Thanks for any help here.

[41Fordor]

Too hard to drill, like an easy out. (Ask me how I know)

I used a Dremel with "Oregon" brand chainsaw sharpening bits to grind it out. Wears out a bit about every 1/16 inch but got through it. Dremel stones are worthless BTW

[danliveshere]

John you need to place a thick flat washer over the hole and then a nut over the washer so that you weld inside the nut to the tap and minimise the weld on the steel.The hole in the washer needs to be just a little smaller than the5/16" you have tapped. If you don't weld to the steel ,it should wind straight out.

[19Fordy]

I broken one off in a piece of "unobtanium" and took it to an EDM shop. But here are some other methods. I think covers it all.

http://www.waltontools.com/products/remvtap.htm

http://www.hotrodders.com/forum/broken-tap-71739.html

http://www.metalartspress.com/PDFs/R..._Fasteners.pdf

http://www.cruisersforum.com/forums/...tap-22870.html

http://www.chemical-supermarket.com/...Fapl7AodB2uHDg

http://www.engineeringhobbyist.com/p...val/index.html

http://www.floridaame.org/discus/mes...tml?1064179241

[Kube]

If it's on a piece you can take to a machine shop, you can have it burned out. Easy to do and shouldn't cost too much. Won't damage the surrounding steel. You can also purchase tap extractors. They are very inexpensive (about $8) and work fairly well. They can be purchased at a good tool supply place, not Sears
That appears to be a three flute tap. The extractor has three 'fingers' that slide down the sides of the tap. A small collar fits over the extractor and you then turn the top. You must go easy and a little back and then a little forward.
Same with tapping... go in a little, back off to break the cut and then go a bit further. If it's a blind hole, remove the tap now and then and clean the hole out. Patience is the key

[richard crow]

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you can get a dimond drill bit yes there is such a thing & they work .when i was an apperance maney years ago i was thought to grind a circle around the shaft of the tap near the square .not to deep the purpose was that if you over loaded the tap it would brake there & make for e z removel. it always worked for me in over 60 years as a mech i never got in trouble with a tap. also onley buy american made taps those bargin taps are good for nothing.

[Ronnie]

Tig welding it is a possibility depending how much carbon is in the tap try the washer and nut idea to get a start.I have done it with success.
Hope this helps. My 2¢

Ronnie

[Henry/Kokomo]

John - One other thing. . . it looks dry around the hole. Don't forget to use cutting oil when tapping steel, kerosine (or similar) for brass and nothing for cast iron. Like previously said, when tapping go forward 90*, then back up slightly to break the chip formed in the hole, forward another 90* etc., etc. Good luck

[Mart]

You could try getting down the side of the flutes with some long nose pliers - if you use some cheapies you could grind then down a bit, then grab the pliers with a pair of vise grips and try to get it to move.

Just one thing to try before getting mediaevil on it's ass.

Mart.

[cmbrucew]

For what it is worth, most taps are broken when you back up.
Drill the correct size hole and use the recomended cutting fluid.
Be sure you start perfectly straight, and equal pressure on both sides of the handle.


Works good
Lasts long time

[gmc1941]

Originally Posted by john hamilton

OK, now I've done it. Broke off a 5/16" x 18 tap in a piece of 3/8" steel. It's broken off even.
What do I do now? Doesn't look big enough to weld a stud to, or is it?
Thanks for any help here.

Two things, Try using a needle nose in two of the opens or use two harden nails and back it out, oil will help.

[Dave72dt]

Weld a washer to the tap, then if you insist on welding a nut, weld it to the washer. Welding only works when you have good penetration and it's near impossible to do that through the inside of a nut. Then go through your tap assortment and throw out the old dull ones. It'll lessen the odds of doing it again.

[john hamilton]

All good advice and thank you. I'm going to try the washer and nut method. Have tried several of the others but as you could see it broke off inside.

As I pulled the shaft out of my tool handle I noticed "Made in Japan". Duh. Didn't think I had any of those.

Watch this spot and I'll let you know what happened.

[cdan34]

John, A machine shop, not an automotive one, could direct you to where you can purchase a tap extracter with four extensions that would slip down the four flutes on the tap and you may be able to back it out using fluid or cutting oil. Or maybe they would do it for you !

Good luck
Chuck

[cmbrucew]

John
I just remembered something.
Get a can of propane, butane or freon and spray the broken tap until it is frozen.
Then strike it hard once with an appropate size drift punch and hammer.
Hit it like you mean it. the object is to shatter the hard tap. then you can remove the fragments with an ice pick or awl. then retap with a good tap.
Hope this helps
Bruce


works good
Lasts long time

[1oldtimer]

break it out with a chisel or i've used the carbide bit for a dremel tool from home depot (it was $9 or so).

[345 DeSoto]

Gently tap it out backwards, using a hammer and pointed tool in the flutes. After a few taps, it should be loose enough to work back out with a pair of needle nose pliers. Worked for me a few times...

[blucar]

Many years ago I had a cracked exhaust manifold on a Dodge 413 V8 in my RV. Murphy's Law, "What ever than can go wrong, will", caused two bolts to snap off in the head. I drilled the first bolt and drove an easy-out into the hole, the easy-out broke off in the hole, I tried the second broken bolt, same results.... I am in deep do do.
I talked to several shop owners I knew, the majority told me the only solution was to remove the head and take it to a machine shop.
One of the shop owners who I had dealt with for many years asked me if I had a cutting torch, I told him I did had a torch with two sets of attachments, one being medium size and one being a small size for light sheet metal.
The shop owner suggested that I use the smaller torch with a small cutting attachment..... Apply heat to the easy-out and just as the easy-out starts to turn red, hit the oxygen which will cause the easy-out to explode out of the hole without effecting the cast iron.
Needless to say I was very reluctant to try this method, but then I finally figured, what have I got to loose?
I had to work within the confines of the wheel well, I had removed the wheel. For safety I put on my welding leathers, goggles, face mask and gloves, I lite the torch, adjusted it down to a neutral flame and put the heat to the first hole, just as the easy-out turned red I hit the oxygen trigger...POW... the easy-out was gone, same thing with the second hole.
I ran a drill bit into the holes, and then chased the threads with a 3/8" tap... In short order the job was done... I gave my friend a big thanks and bought him a six pack.
I would suggest that if you should consider using this trick, use the smallest cutting tip you have, or can find...

[Dave72dt]

I've found several things to be leading causes of broken taps, having broken my share over the years. Dull taps come in as number 1. These are cutting tools, same as drill bits and get dull from use. Dull taps tear the metal out instead of cutting and leave ragged edgs and cuttings and turn hard. The cutting edge is gone and you're actually wedging the tap. Lack of lubrication dulls them faster. Not removing the cuttings often. I keep a blow gun handy to get all the chips out. When buying taps buy the ones with the fewest flutes. It gives you the most room between the flutes for debris. Taps commonly found with 4 flutes, look for ones with 3. Those with 3, look for ones with 2. They usually have a heavier center and wider cutting edges.

I've tried and used most of the above methods successfully except the freezing. They're already hard and brittle. I've also never had to weld on one either to get one out but if you're down to that, the washer welding will give you your best shot. I've used on numerous broken bolts and is my first choice. Much faster than drilling.

[richard crow]

blucar john said he broke the tap off in steel . that system onley works on cast iron. if you try that on steel the whole thing burns.