Please Note: All fractional sizes that are shown with air fittings are BSP/NPT (they are not actual and it causes great confusion)
We have a rough guide to working out your air fitting with some measurements that will help.
1⁄8" male outside thread diameter is approx. 3/8" (9.5 mm) in diameter
1⁄8" female inside thread diameter is approx. 11/32" (8.8 mm) in diameter
1⁄4" male outside thread diameter is approx. 1/2" (13 mm) in diameter
1⁄4" female inside thread diameter is approx. 15/32" (11.8 mm) in diameter
I hope this helps -
Also note that Paasche, Badger and Aztec have their own thread size off the airbrush so you will need either an adaptor or a hose that is that particular brand. Its confusing and many of our customers have problems getting their heads around it all. We get these questions every day so sometimes its best to give us the brand and let us work it out for you.