ASA (Air Standard Adapter) Dimensioned Drawings:

Cadkey Part File

Note that this is not any sort of canonical ASA drawing - it's simply based on measurements that I've made on various regs and tanks.  Many of the dimensions are rather flexible - an ASA makes an airtight seal not via the threads (like a 1/8" NPT connection) but by the o-ring at the top of the ASA.  Hence, the size of the o-ring groove should not be changed too much from what is shown.

Note that the ASA uses CGA 320 threads.  For more info on CGA 320, see

Also note that the drawing is meant to be used when single-pointing threads on a lathe - the drawing is not suitable for making a female ASA!  For female ASA threads, use a 1/2 NPS tap (that's a straight tap, not taper).

Fun fact: Tippmann invented the ASA...