A fastener system for fastening the components of a plastic unit which has a U-shaped clip with an aperture therethrough, a walled cavity to receive the clip, and a machine screw. The walled cavity is molded onto the host portion of the plastic unit and has a low mass, which precludes the formation of sink marks and holes on the plastic unit. The U-shaped clip rests upon the walled cavity and has barbs that bite into the walls securing the clip in place. The machine screw is inserted into a housing on the joined portion of the plastic unit and is mated with a lead thread on the aperture of the clip. The metal-to-metal contact of the machine screw and clip permits repetitive assembly and disassembly of the plastic unit. The clip is readily removable for recycling the plastic of the unit.