Fastener assembly for a power actuated tool

A fastener assembly for use with a power actuated tool, comprising:

• an elongate drive pin having an annular shank including first and second opposite ends, said first end of said shank including a head and said second opposite end of said shank being tapered substantially to a point, said shank including a first longitudinal portion having a first predetermined diameter and a second longitudinal portion having a second predetermined diameter, said second longitudinal portion being positioned between said head and said first longitudinal portion and having a larger diameter than said first longitudinal portion;
• and
• a clip member having first and second opposite sides, said first side capable of engaging a desired surface into which said drive pin is driven and said second opposite side including a tubular chimney portion extending therefrom a predetermined distance, said chimney portion being formed as a continuous substantially annular member having a central bore extending through said chimney portion and said clip member, said bore including a longitudinal portion thereof having a substantially delta shaped cross-sectional configuration where three corners forming the delta shape are rounded off with a predetermined radius, the size of said bore being selected so that the annular periphery of said first longitudinal shank portion makes point contact with three sides of said longitudinal portion of said bore proximate their midpoints for press fitting engagement therewith to releasably retain said drive pin within said bore prior to use, each side of said bore further providing a weakened area at each of its opposite ends spaced about said chimney portion for promoting controlled, uniform expansion and outward curling of a distal end of said chimney portion upon driving said second longitudinal portion and said head of said shank into said bore.