On 20 Jan 2005 09:14:31 -0800, jim rozen wrote:
In article , Dave Hinz says...

Can you use the lathe to turn the stock, and use a die to cut your
threads,

A die won't give a precision lead to the part. Because this is
a leadscrew for the lathe, that's not the best way to make
the part.

Ah, I missed the part about it being a lead screw for a lathe.

Leadscrews not only have to have the correct thread geometry,
but they are effectively length standards in and of themselves.
A die-cut leadscrew would work, but it would impart all the
lead error into whatever parts were then fabricated when
using it on the lathe.

So...how does one cut a clean leadscrew when one doesn't have
a clean leadscrew to start from? Someone made the first one...