A plastic covered fastening device and method of assembly wherein a rigid pin is first inserted into an elongated tube made of a resilient, plastic type material with memory, the tube then being stretched by an axial tension force to reduce its external diameter during installation of the tube and pin into coaxial apertures provided in a pair of elements to be operatively secured to each other, the tension on the tubing then being so that the pin is held firmly in place in one of the apertures as the tubing expands, excess tubing then being removed, as by cutting, at opposite ends of the pin.