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[Boz330]

I broke a 6-48 bottom tap off in a scope block attachment hole. Got a broken tap extractor, but not having a lot of luck with it. I hate to try and bust the remaining portion of the tap up to get it out. Any suggestions. It has been 30 years since I last broke a tap and I don't remember the extractors being that efficient at the job.

Thanks
Bob

[Wicky]

Try this thread:
http://castboolits.gunloads.com/showthread.php?t=30112&highlight=broken+tap
Good luck!

[docone31]

Yeah, I have broken my share of taps also.
What I do,
I use a Foredom handpiece in my jewlery manufacture. I chuck a small diamond bit and cut the tap in half inside the hole. The pieces then can either be pulled out, or spun out.
A ball burr will do it also.
Diamond burrs need speed, and light pressure. Lots of lube. Find one that fits inside the flukes, and cut from the inside out. The void is enough to loosen the flukes on both sides of the cut out.
Now, when I order taps, I also get corresponding drills. I start with a small hole. I can drift that in whatever direction I need to. From there, I use the drill that fits the tap. My first drill bit, is #67, .032. That gives me a lot of lattitude to drift the initial hole if I need to.
Taps do not cut real well with HSS. That is why I have used diamond burrs.

[Boz330]

Thanks guys!!!!! I have some diamond burrs on the way, but I'm going to give the freezer trick a try first. A # 6 tap is small and not much room for error. This barrel hasn't had the first round through it yet and I don't need a $300 tomato stake.

Bob

[elk hunter]

Boz330,

I have used carbide dental burrs, that I get free from my Dentist, in a Dremel tool to cut up broken 6-48 carbon steel taps. I use carbon steel rather than HS taps just for that reason. Also I use one new tap per hole and then throw them away or make bottoming taps out of them so they are sharp. When all else has failed I have drilled them out with a solid carbide drill bit using my Forester jig to guide the drill.

Good luck.

[725]

Just this week I froze a stuck piece for half an hour and first attempt to remove the broken piece was successful and easy. There is hope.

[JIMinPHX]

What kind of tap was it?

Material - Carbon steel? High Speed Steel?

Geometry - 2-flute?, 3-flute?, 4-flute?, Spiral Point?, Standard Hand Tap?, Chip Extractor?

How deep is it?

How deep is the hole?

How many turns did you take since last clearing chips?

Does any part of it protrude above the surface of the work piece? If so, how much?

[Boz330]

OK I stuck the rifle in the freezer for what turned out to be 6 days. I forgot to take the tap extractor home Friday which was when I planned to try and get it out. Monday I had to work late so no joy there. Last night I pulled it out and tried to extract the tap, at the point that I was starting to get concerned about the fingers it broke loose and came right out.[smilie=w:
Prior to that I had taken the preasure to that level and tried heat as well but no joy. On the thread that Wicky had posted there were a lot of formulas and reasons given for why this wouldn't work, but in reality it did, and I am sure glad. I got some diamond burrs and was ready to go that route if needed but was real leery about messing the hole up. Same thing for breaking the tap up which was suggested by quite a few folks on the other thread. I used to work for GE Jet Engine division years ago and one of my jobs was to get broken taps out of Titanium engine cases so I'm somewhat familiar with most of the ways mentioned, but nothing this small.
BTW this was a carbon steel tap from Brownells 3 flute. I bought the set back in the early 90s and have mounted quite a few front and rear peep sights with it so Elk Hunter might have the best idea although I hink you ought to be able to get more that one hole per set, but maybe 15 years might be pushing it.
Thanks again guys for all the suggestions. Keep in mind the freezer trick though.


Bob

[JMax]

I am tucking that idea away so if I need it I will have a solution.

[Junior1942]

What is a diamond burr? Some sort of super hard bit?

[725]

Did it again. This time I stuck a case in a seating die. Not wanting to wrestle with the mess. I stuck the die in the freezer, and when I came back from diner, it came right out with a tug.

[Boz330]

What is a diamond burr? Some sort of super hard bit?

It is a bit that is impregnated or coated with diamond dust or bits. Dentists use them for drilling teeth. To be honest I have never used any before but they are supposed to go through hard steels like a hot knife through butter. You are supposed to run them at very high speed with plenty of lubricant and don't lean on them too hard, they are pretty small.
If you read the thread that Wicky posted above there is probably more than you ever wanted to know about that and tap removal. It is imformative though.

Bob

[elk hunter]

Boz339,

The reason that I use one tap per hole is the cost of a carbon steel 6-48 tap is cheap compared to the aggrivation I get when I break one off in a rifle, especially one that doesn't belong to me. Using new, sharp taps just helps keep my blood pressure where it should be.

Regards

[docone31]

Yeah, I agree on that one. Especially on recievers like the 03-A3. I get them in packages of six. When I am running the tap, if it feels slightly "loose", I switch it off for a new one.
Most of the taps I have snapped however have been from useing something other than a tap handle. Useing an adjustable on the tap is a sure fire way to learn how to remove a broken tap.
Been there, done that. I did learn from it though.
Diamond bits cut very finely. They MUST be spun fast, and well lubed. If the burr is spun too slowly, or too much pressure on it, the diamond plateing will be shed, and the soft steel underneath the plateing will wear so fast it is amazing!
That is also why I use them in cutting tap tips that are stuck in the piece. If I am off line in my cutting, it is not that much. I can correct it as I go.

[Boz330]

Boz339,

The reason that I use one tap per hole is the cost of a carbon steel 6-48 tap is cheap compared to the aggrivation I get when I break one off in a rifle, especially one that doesn't belong to me. Using new, sharp taps just helps keep my blood pressure where it should be.

Regards

I can understand that. Compared to the hassel that you don't get paid for in that sort of situation it makes perfect economic sense. I am a hobby gunsmith so the PIA is all mine.

Bob