What kind of unholy thread is this!

[bradleyheathhays]

I'm setting up some pneumatic lines and I've come across a thread size I haven't seen before in quick disconnect fittings; and because I haven't gotten a grasp yet of how odd pipe sizes work I thought I should ask before I started ordering random parts, which is my usual MO.

I need a fitting that fits the thread in the first picture and plugs into my regular quick connect air hoses.  The part (for comparison) underlined in red is labeled a 1/4" male connector by the kit it came in, and although it looks like it'd fit the hole it doesn't.  So, does that make the one that does something like a 1/8"?  I'm not even sure if quick connect fittings come with that size thread.  Everything that comes up when I search for 1/8" is a push to connect fitting.

I know I could just put a hose over the barb, clamp and call it a day.  But that still requires getting more parts, and if possible I'd rather have it fit into what I've already got.

 

 

[Coop]

The male end looks like it is course straight threads like the end of a water hose and not tapered. 

[bradleyheathhays]

I think you're right on that straight connection.  I'll bet a 1/8" NPT wrapped in teflon would fit ok, especially since I'm just using this for air.

[Tom King]

1/8" NPT is going to be pretty restrictive unless for some special purpose that doesn't require much air, like clamps.   What is that Hex on?  Is it threaded onto the pipe, and what is under that aluminum plate?  Maybe it was for a gauge.  Need more of an overall picture of what the setup is.

There are quite a number of different types of quick-connects, even in the same size.  There are probably at least a dozen different 1/4" types that won't work together.

I'm running 3/8" type H Milton on everything, but really only because that's what I started with in 1975, and there are Way too many to be worth the trouble to switch now.

[BonPacific]

Shot in the dark here, but could that brass part be BSPP (British Standard Parallel Pipe)? It'd be very similar looking to the more common NPT (most air connections I've encountered) or BPT (what you'll usually see on air brushes) but parallel so it wouldn't fit into a tapered female thread.