Thread sizes

[Babalui]

Another set of questions :)

Whats the thread on ASA adapter? 1/2" NPS ? Are there any variations in that thread, like fine, coarse?

Whats the thread on front LP chamber (the one that screws into fornt part of vertical adapter) ?

Thanks in advance

[bigred76]

If anyone knows it, it'll be in here: http://www.spyder.tv/forums/showthread.php?t=223

[Babalui]

Only screw sizes there, and for ASA it says 3/4" x 14 NPT. But when I google around, I get only 1/2" NPS and CGA 320 (0.825", 14 Teeth Per Inch). I'm not all that familiar with non-metric measurements, so if I'm going to make my own ASA, what type of tap should I ask for?