Scuba fitting specifications

Mar 01, 2005 7 Replies
R

Anyone know the dimensional specs for the 3/8-24 and 7/16-20 straight threaded fittings used on scuba regulators and hoses? I don't mean the inside and outside threads themselves (they are UN spec), but the face that mates to the O-ring. There are several steps in the face of the female fitting which I would like to be able to machine myself.



It may be something like SAE J514, but that's not quite right.



See "HP & LP Scuba Adapters" here for some (fuzzy) photos:



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Here's 7/16-20 hydraulic adapter that looks like a male scuba fitting (the O-ring side on the right, not the flared end):



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Grainger just calls this "SAE standard", and I'm not sure if this is the same as used for scuba or not.


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T

Most likely one of these three: MS(like MS33649) or AN (like AN10050) or SAE (either 514 or 5202)

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We usually cut them with porting tools from Wetmore or Tosco.

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G

Try "rec.scuba.equipment" or "rec.scuba"

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R

Yeah, I figured some metalworking types would be more likely to know the technical details. The rec.scuba.* is about brand X vs brand Y, not about what you make in your own shop.

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R

Your references above all have 120 degree beveled cuts on the outermost step; the scuba fitting has only a square step.

Here, I made a drawing of my measurements that have worked for me, although I would like to have the actual specification:

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R

Let me correct what I said above. After examining some typical ports, it is apparent that they do have a bevel or taper where the O-ring seats on the female side.

I've thoroughly Googled and Deja'ed this issue and I can't seem to find any hits at all on it, other than some non-specific comments about the fittings being "SAE".

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T

If you take some rough measurement and post back with them it would help.

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R

Again answering my query after some more searching, it seems that the SAE J1926 standard seems to match well. This was reproduced as a military standard MS16142 which is available at

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although this has been cancelled in favor of just referencing the SAE document (which costs $$ to download).

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