METHOD OF CALCULATING AN AVERAGE PLATING THICKNESS T OF A TUBE FITTING

A tube fitting includes: a zinc-based plated layer; and a resin coating layer that is positioned at an outermost surface at an outer side of the zinc-based plated layer and includes a polyethylene substance, a lubricant, and solid particles. When a fitting average plating thickness t relating to the thickness of the zinc-based plated layer is defined, 2.1 < t < 19.7 is true.