[GTALUG] Surveying

[Howard Gibson]

On Sun, 24 Apr 2016 21:07:23 -0500
o1bigtenor <o1bigtenor at gmail.com> wrote:

> OK - - - so these are part of the rule changes from the late 50's. Its also
> when it went from NC and NF to UNC and UNF and there are lots of
> companies AND people that still use the old designation.
> 
> Rule changes this old shouldn't really be a problem for today's use though.
> 
> Regards
> 
> Dee

o1bigtenor,

   I am a mechanical designer, and I have not seen the terms NC and NF in anything other than my French's drafting book from 1941.  English screws are UNC, and UNF.  The threads on the bottom of your cameras are supposed to be 1/4-20BSW.  

-- 
Howard Gibson 
hgibson at eol.ca
howard.gibson at teledyneoptech.com 
jhowardgibson at gmail.com
http://home.eol.ca/~hgibson