Threading carbide

[KaptainKarst]

Newbie alert!

I am trying to figure out if it is possible to cut internal threads in a carbide tube.

Any suggestions (not even sure if there are different grades of carbide)?

Thanks,

[mxtras]

Cutting? No. On second thought - I guess it would be possible with diamond tipped tooling.

Grinding? Yes - easily. Well.....you know what I mean.

EDM? Don't think so, but I guess it's possible?

There are air hardening carbides that are machinable in their semi-annealed state but I can not remember for the life of me the name of the materials. Ferro-tic comes to mind. Maybe something you could Google if it applies.

Scott

[ErnieD]

Hi,

In regards to putting internal threads in carbide! I have a friend who gets a lot of jobs where he has to put threads in tool steel ( D2 ) to correct or change the size or location of the holes. He is located near Toledo, Ohio. If you are interested I can put you in touch with him. He does this in an EDM machine and the machine can handle carbide as well.

Ernie

[Mcgyver]

Kaptain, can you share with us what your'e trying to do? If only for curiousity, but you may find there are other ways to skin the cat the smart peeps here could suggest

[KaptainKarst]

I exploring possiblities for a friend who needs a small diameter tube (~.5" od and ~.3" id x 1.5" long) threaded on the inside of one end.

The tube needs to be carbide to withstand the operating conditions but needs to couple to a flexible cable that has a threaded connector on it.

Sorry I can't be more specific, hope that is enough info.
Thanks

[Mcgyver]

braze an adapter to the carbide? loctite if it can handle the environment?

there are lots of things i don't know, but i'll go out on a limb on this one....your not going to thread .3 id carbide, failing some special machinery like the edm mention (although you edm threads is a mystery to me) maybe thread milling with a diamond cutter? not likely something you'd find a newbie's shop, or and oldie for that matter

carbide (iirc) is sintered - its made from powder. If threads were needed they'd be molded into the carbide as it was formed. I'd guess though that given its brittleness, holding by threads might not work very well? for example if you leave tool steel glass hard the threads aren't going to be very strong because of the brittleness, I'd think carbide would be 10x worse.

[Mcgyver]

3 minutes of googling and i now know you can edm tap

http://www.mmsonline.com/articles/069701.html

still, I'd be inclinded to braze because of how brittle carbide is

[KaptainKarst]

Thanks!!

I just needed to get pointed in the right direction.
Very good article.

[DareBee]

That is exactly how my EDM tapper works. Don't forget that electrodes are custom sized to allow for the overburn.
You can also orbital tap in CNC sinkers (very similar to thread milling) this makes a more accurate thread than the "Tap Rod" method, also takes WAY more time.
Back to the problem at hand, I would not be inclined to tap the CBide, it is too brittle and it may break off the threads.
It would be best to silver solder a CBide sleeve over a steel inner piece.
If you wish to send it here I will tap it if that is what you really want though