Help me with a Fidelity Research FR64 part


I got a mint FR64 tonearm at a great price. Sadly there was a catch it did not have the nut that fastens the arm at the base. It is a really fine thread (25 threads per inch) in fact my machinist doesn't have tooling for this.

so I want to know if anyone out there knows where I can get the said nut, or if they have one they can sell me - thanks
parrotbee
Most of the machinists i have met are not interested to make just one small part, it is not interesting for them and they are busy with some serious orders. Unfortunately we're not their customes with one nut or one screw or anything like that (cheap parts).  
As I mentioned at the top of the thread (I think), I DO know a machinist who most likely would make this single nut for the OP, if he is given the correct specifications to work from.  That is Colby Lamb in Oregon, USA. I can provide contact info, if desired.  Colby made me a new threaded retaining ring for my SP10 MK3 platter; without that part it is impossible to fix the platter in place.  It sounds like the needed FR nut may be M30 (30mm diameter) with a metric pitch of 1.0.
this thread is turning me absolutely nuts - some may think I am unstable :) 
24 and 26 TPI is quite standard 25 is not - trust me I searched... Also bear in mind the odd diameter as well
Parrotbee
Most of the worlds population work with the metric sysrem. The population of Japan belong to this club
As Lewm suggests, this appears to be a M30x1 thread. 
It is defiantly a standard thread. 

Neither the thread pitch or diameter are unusual outside of USA

cheers 
Parrotbee, Metric pitch is not measured in "threads per inch".  The inch is not a unit of distance in the metric system.  However, one inch = 25.4 mm.  The millimeter, etc, IS a unit of distance in metric. If you count 25 threads per inch, that would equate to one thread per mm, which is expressed as a (metric) pitch of 1.0.  In the metric system, THAT is a standard pitch, albeit a "fine" pitch for an M30 part. (Metric has "coarse" and "fine", much like SAE.). The platter retaining ring for my SP10 Mk3 is M18X1.0, for another example.