Sponge head retainer pin

摘要

The retainer pin includes a plurality of longitudinal rows of radially extending wings about a circumference of a shank. The radially extending wings within any one row are longitudinally offset from longitudinally adjacent wings by a pitch. The wings of circumferentially adjacent rows are offset by a distance equal to one half of the pitch thereby forming a double helix. The double helix configuration of the radially extending wings creates a screw-like configuration which is used to engage a partially threaded aperture.