A method for manufacturing a tube fitting includes steps of: preparing the tube fitting; and forming a resin coating layer upon a coated region provided upon the surface of the tube fitting. Forming the resin coating layer includes: dipping the tube fitting into a coating material that includes as components a polyethylene based substance, a lubricant, and solid particles and having viscosity within a range of 4.24 to 5.27 mPa·s at 25° C., and adhering the coating material to the coated region; and, drying the coating material which is adhered to the coated region of the tube fitting. In the dipping step, the mass per unit area w is controlled within a range 0.79