Drill/tap a cat-40 toolholder?

Awl --

For 3/16 endmills, sandvik.

Dat toolholer is so hard....

HOW HARD IS IT??

It's so hard, I cain't hardly SPOT it, much less drill/tap it....

The old set screw/hole is gone... and I mean literally, as a slot now exists where the old set screw was.... long story.

So I could proly drill a tap hole with a carbide drill. Will I need a carbide 8-32 tap? Cut or form?? Should I rigid tap it, tapmatic it, or hand tap it? If a cut tap, 2, 3, 4 flutes??

I'm into this already for proly what a new import would have cost me.... goodgawd....

Reply to
Existential Angst
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I would think your success would depend on how deep the case was and or if it was through hardened.

If it were me I'd buy a new one. Carbide drill and tap I would guess would be close to the price of a new one.

This guy is US based and many people on Practical Machinist have had good results with his tools:

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Best, Steve

Reply to
Garlicdude

Typically the hole is slightly offset, and drilling a new setscrew hole will push your tool off center. Quit F##king around. Let Banquer be the designated idiot. Get a new holder from Frank Mari. He is a good guy to deal with.

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Reply to
Cross-Slide

You can't wreck this thing as it's broke. Put in the heat treat oven in tool wrap with reduction materials, match sticks/paper. Anneal it, let cool slowly in wrap. Machine the new hole and threads. I would assume this is not A2 tool steel, so I would put case hardener on it, run it back up to temp, drop in water. Then buff the surface munge off, and hope it's still concentric enough for your 3/16 endmill and task at hand to not be a problem. If it's now junk, your where the other posters said to go, and buy a new one. ignator

Reply to
ignator

Sandvik uses a steel called THG 2000 for most of their tool holders. Normally they are case hardened with a surface hardness of 60 HRC and a core hardness of 50 HRC.

Carbide drill & tap will work a treat (50% thread depth is plenty enough) but if you need to buy the tooling - forget it, and get a new holder. You might get away with using a HSS tap, but you'll need to regrind the tap by hand a couple of times before you're finished.

Reply to
J. Nielsen

Toss it into a good bonfire and let it cool in the ashes till it's only warm to the touch...at this point it will probably register in the 28 Rc or so range.

BTW, for endmills having shanks smaller than 3/8" IMO collet chucks are almost always a better choice.

Reply to
Uhh Clem

Ouch!

If it is *that* hard -- there is no way that I would try a form tap on it. Form taps depend on a certain amount of ductility in the workpiece. If you can barely start a spot drill, I don't expect much luck.

Carbide tools are quite brittle. The drill -- in a good drill press, with the workpiece held firmly clamped to the table might survive.

However, I would consider a sold carbide tap to be quite likely to shatter when you started cranking on it.

A CNC controlled properly shaped grinding point could be used to grind a new thread, I guess. But for 8-32 threads -- that would be awfully tiny. Better to tap it when it is annealed and *then* harden it.

A used CAT-40 tool holder isn't worth all that work -- especially with a chunk broken out where the threaded hole used to be. Among other things, this probably means that your new threads will be pushing the shank away from the position which gives the minimum TIR.

I agree. Even the price of a new made-in-USA one, let alone the price of an import one.

Good Luck, DoN.

Reply to
DoN. Nichols

Heh, apropos of the unanimous opinion here, I guess I have butt another paperweight. It all started with a super-stuck set screw. Hindsight makes it clear I shoulda just soaked the g-d thing in Kroil or PB Blaster for a day, which may have scared off the Poltergeist, who then broke off an allen wrench in sed set screw, who then broke off an endmill in sed combined allen wrench/set screw.

I must say, tho, a 4.5" angle grinder made short work of it all! It was sort of my effing revenge.

Since it is a lost cause, I may O/A the nose, just to see how drill-able it becomes -- if I'm bored. 60 rockwell?? goodgawd..... no wonder I couldn't spot it.... Seems like overkill for a g-d 3/16 toolholder....

Re the comment of using a collet holder, the nice thing about these small endmill holders is the small nose -- which imo could be even smaller, given the light-ish loads of a 3/16 shank, and often smaller ends.

Appreciate the links.

Reply to
Existential Angst

Uhh, dat would be FUTURE sight, no? That's also pushing my paradigm-ic envelope, but indeed is some good advice. Jetlube (canada) makes a number of anti-seize products. Which one do you use?

Reply to
Existential Angst

PB Blaster for a day,

In hindsight you should immediately buy yourself a can of jet-lube or similar moly paste and apply some of it to the setscrew on every holder in your inventory because if you don't then this is going to be a recurring problem.

Reply to
PrecisionmachinisT

This which works well for the occasional sticking taper shank and is also good on nuts bolts etc but will quickly wash out in an oil bath:

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And then there's this bostik non-moly product which I usually use on fasterners such as endmill holders and such--also good stuff to coat bellevilles with as when replacing your drawbar springs.

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Reply to
PrecisionmachinisT

If it doesn't come loose without much more than the usual and expected effort ( say for instance with a modest length of cheater pipe and a NEW allen wrench ) then put it into a preheated oven at 250 degrees or so and let it heat soak for 1/2 hour or so--then while it's still good and hot use a pair of tongs and dunk it business end first into a coffee can that's been filled 1/2 way up with a 60/30 mix of wd-40 and ATF--( it will smoke like crazy so suggest do this outdoors )--upon this rapid cooling some of the oil will vapororize and infiltrate the oxide matrix turning it from a solid into a sort of greasy film and thus releases the mechanical bond while also lubricating the mating surfaces.......

Afterwards, put a cover on the can and save it--for to dip your holders, collets, endmills lathe holders, etc into. before putting them into longer term storage...

Reply to
Uhh Clem

Need a couple of pure carbide drills. I have carbide center drills. They take the tough stuff. I drilled through some Mo-Max to make a form tool.

Mart>> Awl --

Reply to
Martin H. Eastburn

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