I'm building a small pneumatic control cabinet with a couple filters, regulators, valves, and flow restrictors. I had started by using 8 mm push-to-connect fittings and nylon tube, but it seems I can make things more compact by using metal tubing.

Thing is, I'm having a hard time finding any kind of basics tutorial for how one does this. I've seen a few photos, and found a couple pipe-bending tutorials, but I don't know what kind of fittings to use.

  • It seems I can use flared fittings, is that what's usually done?

Unfortunately, I can't find metric sizes on McMaster-Carr, so I'm going with 5/16". But while they have aluminum tubing and bending tools for 5/16" OD tubing, they don't have fittings. They do have 1/4" and 3/8" fittings.

  • Can I under- or over-size the fitting and the pipe like that?

  • Are there any good resources for learning how to fabricate a control system using metal tubing?

  • The thing I'm controlling is the tool changer on a nice spindle motor. It has 8 mm OD push-to-connect fittings, 6 mm ID tubing. 3/8" metal tubing has a 1" bend radius, while 5/16" tubing has an 11/16" bend radius, allowing for slightly more compact layout.

  • 2
    $\begingroup$ Parker $\endgroup$
    – Phil Sweet
    Nov 4, 2018 at 12:53
  • 1
    $\begingroup$ I expect you are talking about modest pressures , like under 200 psig. $\endgroup$ Dec 4, 2018 at 22:04
  • $\begingroup$ Yes. 0.5 bar and 6 bar, maybe 11 bar input pressure. $\endgroup$
    – Rick
    Dec 4, 2018 at 22:12

1 Answer 1


As far as I know, two commonly used systems are cutting ring fittings and press fittings. Note that both need some space for installation.

You should talk to a pneumatic components supplier, there are systems where you simply push the pipe into a connector (no english link at hand).


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.