A threaded joint for tubes

Threaded joint in which the threads are coated with a layer of dry lubricant with a thickness included between 5 and 30 um and in which the nominal void volume NVV of the space [6,7] between the thread of the male tube and the thread of the Female tube is dimensioned using the following NVV formulas (cm ^ 3) <= 4 * OD (inch), [NVV (cm ^ 3) / OD (inch) * SQR (Wt (mm))], Gr <= 0.4mm ^ 2 / pitch where OD is the nominal outside diameter and Wt is the wall thickness of the pipes.