I am trying to thread a 3/8" diameter Tungsten metal rod on the
lathe. I have already killed a WC tipped thread tool. Anyone have
any recommendations on the proper tooling for threading this difficult
to machine metal?

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In article , wrote:
I am trying to thread a 3/8" diameter Tungsten metal rod on the
lathe. I have already killed a WC tipped thread tool. Anyone have
any recommendations on the proper tooling for threading this difficult
to machine metal?

Machining tungsten is VERY difficult. It work hardens if you look at it
crosseyed, and then it gets nearly impossible to deal with. Just
drilling a hole in an "easy to machine" tungsten copper alloy requires
constant feed. If you hesitate for a second, you're screwed. I've never
tried threading it, but it might work best if you can do it in one pass.

Good luck.

Doug White

Grind the threads in with a formed diamond wheel and a toolpost
grinder

Bob

wrote:
I am trying to thread a 3/8" diameter Tungsten metal rod on the
lathe. I have already killed a WC tipped thread tool. Anyone have
any recommendations on the proper tooling for threading this difficult
to machine metal?

If the application of the tungsten rod will allow, Id not thread the rod
at all.
Id braze on a steel sleeve then cut the thread into the steel.
should hold up to a reasonable load.

On Thu, 24 Jan 2008 15:31:08 -0800 (PST),
wrote:

I am trying to thread a 3/8" diameter Tungsten metal rod on the
lathe. I have already killed a WC tipped thread tool. Anyone have
any recommendations on the proper tooling for threading this difficult
to machine metal?

One of the finest machinists I've ever had the privilege to work with
worked for one of my customers - a place that processes refractory
metals, including machining tungsten. He told me that he did single
point a thread on a pure W rod once, as a stunt. As I recall, he said
he had to resharpen a carbide tool after every couple passes. I know
that they used to use trichlor for coolant, and the older guys there
get kind of misty-eyed when they talk about how great it was for
cutting tungsten.

As far as I know, if threads are required in pure tungsten, grinding
is the preferred way to cut them.

--
Ned Simmons

"Ned Simmons" wrote in message
...
On Thu, 24 Jan 2008 15:31:08 -0800 (PST),
wrote:

I am trying to thread a 3/8" diameter Tungsten metal rod on the
lathe. I have already killed a WC tipped thread tool. Anyone have
any recommendations on the proper tooling for threading this difficult
to machine metal?

One of the finest machinists I've ever had the privilege to work with
worked for one of my customers - a place that processes refractory
metals, including machining tungsten. He told me that he did single
point a thread on a pure W rod once, as a stunt. As I recall, he said
he had to resharpen a carbide tool after every couple passes. I know
that they used to use trichlor for coolant, and the older guys there
get kind of misty-eyed when they talk about how great it was for
cutting tungsten.

As far as I know, if threads are required in pure tungsten, grinding
is the preferred way to cut them.

--
Ned Simmons

I'd agree that grinding would be the preferred method, but they can be
single pointed. I ran an order of balance screws for one of my customers,
years ago. They were made of tungsten and had to be threaded to some
non-standard sized 80 pitch thread. I recall that I spent a great deal of
time at the grinder, but I managed to turn out the entire lot with care.
I'm sure that the fine thread was to my advantage.

I've machined tungsten for other applications as well. It is tough on tools,
but machines reasonably well. I'd suggest a C2 grade of carbide, and lots
of patience.

Harold

Thank you everyone for your useful posts. The easiest solution for me
is the Steel sleeve-over Tungsten rod, never considered that.

The McMaster-Carr Tungsten costs a small fortune, but a good source
for machinable material nevertheless.

-1911