If its an OD thread, I always roll the threads that small.
Anyone had any luck with cutting 1-72 thd in 304 stainless. I have been all over the place with speeds and feeds, depth of cut. The threads still look like sh*#. Try to cut them on Citizen L20..
If its an OD thread, I always roll the threads that small.
www.atmswiss.com
UTILIS makes a full profile single point insert that would be your best shot at cutting that fine thread.
Page 59, Part No. 1606-01-72-UNF 60 VPR UHM30 HX
http://www.genswiss.com/UTILIScatalog2010.pdf
While I do like Utilys tooling, I'm in the rolled thread camp for threads that small in 304. A material such as 303 cuts with far less force, something to be considered with small threads.
Allouette Tool of NY sells the Habegger 3-roll dies in those small sizes, and they work nice.
It's would helpful if the poster let us know what is the length of the thread he's trying to cut. Sometime this can cause by not setting the tool center(core) correctly. I don't see any problem of cutting this size on a L20.