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Need some help drilling and tapping grade 2 Titanium

SMT

Hot Rolled
Joined
Dec 9, 2010
Location
PA
In the mill -

4-40 thread, 2.3mm tap drill (so 65%ish thread) No trouble drilling, however, taps explode without fail. We're using dormer/regal taps for Ti, Union Butterfield tap goo and have good rigid tapping on an 8 month old Okuma M560v.

I have an extensive tooling background and my guys aren't stupid but this one's getting the better of us. We have resorted to bringing in threadmills which I think should work fine.

But what the heck? We've tapped hardened steel and super duplex stainless with ease.

In the lathe-

.043" drill. We're spotting just a hair to make a pit, 1400rpm or so and .001 feed, .02" peck. That seemed to work for 6 parts or so. That's using a regular old black oxide jobber drill. All the high perf cobalt drills (Nachi) broke immediately (didn't even get one hole) Called them and ran their data, no luck.

I have more of those jobber drills coming since they at least kind of work but damn, I did not expect this.

Curious how you all do it. Note, Grade 2 is softer than 6Al4V
 
In the mill -

4-40 thread, 2.3mm tap drill (so 65%ish thread) No trouble drilling, however, taps explode without fail. We're using dormer/regal taps for Ti, Union Butterfield tap goo and have good rigid tapping on an 8 month old Okuma M560v.

I have an extensive tooling background and my guys aren't stupid but this one's getting the better of us. We have resorted to bringing in threadmills which I think should work fine.

But what the heck? We've tapped hardened steel and super duplex stainless with ease.

In the lathe-

.043" drill. We're spotting just a hair to make a pit, 1400rpm or so and .001 feed, .02" peck. That seemed to work for 6 parts or so. That's using a regular old black oxide jobber drill. All the high perf cobalt drills (Nachi) broke immediately (didn't even get one hole) Called them and ran their data, no luck.

I have more of those jobber drills coming since they at least kind of work but damn, I did not expect this.

Curious how you all do it. Note, Grade 2 is softer than 6Al4V
.
tap hole by hand and feel how hard to turn.
.
some material like aluminum bronze are picky on tap type to use. use wrong tap and they turn hard and break. might have to find a tap type that works with your titanium
 
.
tap hole by hand and feel how hard to turn.
.
some material like aluminum bronze are picky on tap type to use. use wrong tap and they turn hard and break. might have to find a tap type that works with your titanium

Tried that. Called mfgr and asked what they recommended for Grade 2 Ti. Got those tools, ran them the way they said and had failure.
 
Tried that. Called mfgr and asked what they recommended for Grade 2 Ti. Got those tools, ran them the way they said and had failure.
.
i have had bad taps before. heat treat problem and they break easy. hand tap and see how hard they break. if they break too easy then it is not the titanium so much as bad taps
 
never worked with grade 2 but I can imagine it's a bitch. would a forming tap maybe be an option? sucks that it's a tiny 4-40 thread.
 
I had to tap a bunch of .4,.5 and .6mm holes in titanium. I asked what grade it was repeatedly and never got more than "we think it's grade 4". Regardless, went for similar ~65% thread, one piece of stock would produce 3-4 holes per tap, another would need 2 taps per hole. Taps in this size are hard to find in the myriad styles available in larger sizes, so we just went with the flow.

4-40 I would imagine you can find specific taps if you call the big makers.

Drilling's no fun either. We settled on hss with little to no peck if possible and the highest feed it would take. Step drilling was a disaster. Tried all sorts of different lubes from commercial cutting oils to bacon fat to bacon fat mixed with beeswax. Actually pure beeswax was one of the best.

Milling wasn't too bad. Drilling and tapping a nightmare.

One thing for sure- tools have to be dead keen and the moment they degrade it's over.

Still not as bad as machining platinum.
 
I fought some 6-32 in TI and Zirc lately Every one sent down was a dead part.

Feeding it by hand the tap was very sticky/poppy with the Qualichem250C or Tap Magic. Used a little stick Boelube and they cut like aluminum..
 
I found drilling to be no problem. I use carbide drills so I can at least get some RPM. I use the cheaper carbide drills from place like Maritool, nothing too fancy, If it's deep I will peck, after a couple diameters, just to clear chips.

For threads, I threadmill.
 
Hi SMT:
We had success cut tapping Ti6Al4V , # 0:80 4.5 mm deep 56 holes per part not too long ago.
Keith peck tapped them at low (150??) RPM, lots of Rapidtap and I believe 1/4 turn per peck.
It would have been a sphincter clencher for sure except that we have both a sinker EDM and a laser welder.to fix the crunchies if they happen.
He broke only two taps, so it CAN be done, but we got specials from Guhring, and he took his sweet time to run the job.
We locked the doors and turned off the phones too!
Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
www.vancouverwireedm.com
Clarus Microtech Inc. | Facebook
 
In the mill -

4-40 thread, 2.3mm tap drill (so 65%ish thread) No trouble drilling, however, taps explode without fail. We're using dormer/regal taps for Ti, Union Butterfield tap goo and have good rigid tapping on an 8 month old Okuma M560v.

I have an extensive tooling background and my guys aren't stupid but this one's getting the better of us. We have resorted to bringing in threadmills which I think should work fine.

But what the heck? We've tapped hardened steel and super duplex stainless with ease.

In the lathe-

.043" drill. We're spotting just a hair to make a pit, 1400rpm or so and .001 feed, .02" peck. That seemed to work for 6 parts or so. That's using a regular old black oxide jobber drill. All the high perf cobalt drills (Nachi) broke immediately (didn't even get one hole) Called them and ran their data, no luck.

I have more of those jobber drills coming since they at least kind of work but damn, I did not expect this.

Curious how you all do it. Note, Grade 2 is softer than 6Al4V

Gr 2 is goop. thread mill or form tap. if you must cut tap go as big on the tap drill as you can and try emuge I don't know if they make the Rekord series that small but they have a good Ti geometry. Kennametal makes a good carbide drill for ti worth a try or just pump and dump with bright finish HSS stub or screw machine length they should be cheap enough to toss out every couple holes. feed them relatively heavy with low SFM
 
Just to update-

Thread milling is working. We called Emuge and their own tech guy said absolutely don't bother tapping even with their rekford taps. He said threadmill all the way.

HSS jobber drills seem to be the king so far.

I suspect 6Al4V would be easier to drill and tap as it's harder and chips are more likely able to act like actual chips vs chewing gum :)
 
I tap all my titanium parts with M2.5 threads on a drill press using a Tapmatic. Drill the holes 0.1mm oversize from the normal pilot hole on the mill then use uncoated taps for alu, I like the ones from Gühring. Coated taps tend to break, uncoated ones go right through the titanium. Grade 2 is much different than grade 5. I use tapping grease from Emuge, do not try them dry, use a lot of oil if using cutting emulsion.
 








 
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