Air line and valves question... help help help!

[ianrulz123]

I know this is a really dumb question and the answer is probably staring me in the face, but the 11 hour days at my office have fried my brain, so here it goes:

I have 3/8" SMC valves, with 2600 lb Firestone bags. I know that I need 3/8" threads on the fittings, but do I need 3/8" I.D. or 3/8" O.D. air line?

Any help will be GREATLY APPRECIATED, as I plan to run all the line and do the wiring tommorow evening.

Thanks!

ian

[darren@ridetech.com]

Airline is always measured in OD, so you will want 1/2" airline.