You know that feeling, when you make a BIG mistake...

[Atlas Knife Company]

drill and tap before cut the lock or anything else

That may be some of the best advice yet.

 

[Phil705]

When I first saw the photo I thought it was a meteor crater on the moon. Yes, been there done (similar) more times than I care to admit. Hang in there!

ps I am a big fan of your knives. You set a standard I have yet to achieve. Someday I'm going to call you and ask for a shop visit.

 

[Salem Straub]

Hey Thanks Phil. What a nice compliment. You're welcome at my shop whenever. I live closer to town now, too.

 

[balibalistic]

Bro, use a #49 drill on TI. Somtimes even a #48. Since i started using a tapmatic head in my drillpress i use threadforming taps with a #47 drill. thats a real bummer what happened there.

 

[Salem Straub]

Tapmatics are NICE. I used one a couple times, ever since then it's been on my wish list. Thanks for the advice. Will a #49 give me enough thread depth? I could do the math, but I'm lazy right now.

 

[Carl_First_Timer]

Tapmatics are NICE. I used one a couple times, ever since then it's been on my wish list. Thanks for the advice. Will a #49 give me enough thread depth? I could do the math, but I'm lazy right now.

Thread forming taps deform the material so your initial hole size is bigger than a cut tap.

Copy/Paste Job:
Cold Form Tapping—Cold form taps do not have cutting edges or conventional flutes;
the threads on the tap form the threads in the hole by displacing the metal in an extrusion or
swaging process. The threads thus produced are stronger than conventionally cut threads
because the grains in the metal are unbroken and the displaced metal is work hardened. The
surface of the thread is burnished and has an excellent finish. Although chip problems are
eliminated, cold form tapping does displace the metal surrounding the hole and countersinking
or chamfering before tapping is recommended. Cold form tapping is not recommended
if the wall thickness of the hole is less than two-thirds of the nominal diameter of
the thread. If possible, blind holes should be drilled deep enough to permit a cold form tap
having a four thread lead to be used as this will require less torque, produce less burr surrounding
the hole, and give a greater tool life.
The operation requires 0 to 50 per cent more torque than conventional tapping, and the
cold form tap will pick up its own lead when entering the hole; thus, conventional tapping
machines and tapping heads can be used. Another advantage is the better tool life obtained.
The best results are obtained by using a good lubricating oil instead of a conventional cutting
oil.
The method can be applied only to relatively ductile metals, such as low-carbon steel,
leaded steels, austenitic stainless steels, wrought aluminum, low-silicon aluminum die
casting alloys, zinc die casting alloys, magnesium, copper, and ductile copper alloys. A
higher than normal tapping speed can be used, sometimes by as much as 100 per cent.
Conventional tap drill sizes should not be used for cold form tapping because the metal is
displaced to form the thread. The cold formed thread is stronger than the conventionally
tapped thread, so the thread height can be reduced to 60 per cent without much loss of
strength; however, the use of a 65 percent thread is strongly recommended.

 

[David Stifle]

Is the blade ruined too? If not, you could at least use it.

Dave

 

[Salem Straub]

The blade is fine. So is the face side of the frame. I'm still using those- I had the knife apart when I mangled it.

I hadn't been aware that cold form taps existed. The thought that they require more torque than a conventional tap gives me pause, however. Tapping a hole in that thick frame already took a lot of torque. I guess they must be built to take it- I also wouldn't have thought that TI was a particularly ductile material. I notice it didn't mention TI in the above blurb. Not that I'm questioning you, Bali, I just wouldn't have tried it solely on the strength of the above information. I like the part about the threads formed thusly being stronger...

 

[David Stifle]

Well...heck then, it ain't a tatal mistake. use the blade, fix it and move on. It's salavagable. Can't tell you how many times I've had to "modify" my design

Dave

 

[Bigfattyt]

You mean like this dandy I got while hungover Saturday? :barf:

I have had that exact injury on my right pointer finger.

I was working on a bench grinder, when one of my co workers calmly walked up, and flipped the switch to on to grind his parts while my finger was on the wheel! Sucks!










As to the OP, I could have told you that the scales would melt before the hardened steel tap.

Broken taps suck. The smaller the worse it is.

What really sucks is when you break the tap off in the hole, then drill it and prep it for a reverse threaded bold remover, then break that off in the broken bolt end you are trying to get out in the first place.

Sorry to see the trouble.