Bruce
Do you have any 0-30psi Pressure gauges for 1/4-40 or 3/16-40 screw types?
Well No, but I haven't tried it yet. The problem is the stem just barely lends itself to be turned down to 5/16" anything else would need a special stem soldered on.
I Jerry rigged a 1/16 NPT using reducing bushings down to 1/4-40; but it looks wonky.