I've never heard a torque spec for the fittings either...I always go just a bit beyond snug, kind of like AN fittings, takes a light feel on the wrench or ratchet to get them right... I have a set of crowsfoot line wrenches that I use on both, some get a bit tough to reach.... The tubing on the Vintage Air fittings is aluminum, plus the O rings, really easy to over torque the fittings and damage the O ring....