Patent ID: 7374384

Claim:
A fastener comprising: a head having a head diameter, a top surface, and a bottom surface; a single elongate shank having a nominal shank diameter, said shank being integral with said head and extending from the bottom surface of said head along a longitudinal axis, said shank including a tip opposite said head; and a plurality of rings extending outwardly from said shank, each ring having a crest and a root, with the crest being located closer to said head than the root, said plurality of rings having a middle ring located substantially in the center of said rings, wherein said fastener has a bending yield strength of about 100 ksi or greater; said fastener has a length defining the distance from the top surface of said head to the shank tip, the length being between about 0.5 inch and 1.75 inches; the ratio of the head diameter to the nominal shank diameter is between 2.70 and 3.37; and said plurality of rings are formed so that an average outer diameter of the crests of the rings between the middle ring and said head is greater than an average outer diameter of the crests of the rings between the middle ring and the shank tip, wherein an outer surface is formed between the crest and the root of each ring, said outer surface including an angled portion positioned at an angle relative to the longitudinal axis, and said outer surface of a majority of said plurality of rings further comprising a flat portion positioned at an angle relative to the angled portion.