Abstract: The fastener, which is typically made of thermoformed or similar plastic, includes a shank portion at least two parallel fingers which further include a proximal end and a distal end. The proximal end of the fingers is integral with a base portion and the distal end of the fingers is integral with bridge elements which attach to a wedge element. A driving pin is attached to the base portion and is aligned with a gap formed between the at least two parallel fingers. The parallel fingers further include lateral serrated portions and radially oriented stabilizing fins. Upon impact to the driving pin when the fastener is placed into a blind threaded aperture, the wedge portion forces apart the distal ends of the parallel fingers, while the driving pin forces apart the proximal ends of the parallel fingers thereby driving the serrated portions of the fingers against the threads of the blind threaded aperture.