Tube fitting with indicating means and method for measuring proper tightening of cutting sleeve fitting

An intrinsic gauging device for a ferrule type tube fitting (10) of the type having a coupling nut (14), a coupling body (12) and at least one ferrule (32), includes a precisely formed marking on the coupling body that is visually perceptible when the coupling is in a finger tight position, and that is covered or visually imperceptible or otherwise has a predetermined relationship with the coupling nut when the fitting has been initially pulled-up. In a preferred form, the marking is realized as a precision groove (50) or recess machined into a surface of the coupling body. The groove can be made more easily visually perceptible such as by roughening or knurling the surface, or coloring the surface, for example. The groove defines an edge (50b) at a precise position that corresponds to a predetermined axial displacement of the nut relative to the body for initial pull-up. The marking may also be formed with a precise dimension such as an axial length to provide a second edge that corresponds to a predetermined axial displacement of the nut relative to the body beyond initial pull-up for fitting assemblies that are remade.