#12-14 x 1-1/2" bi-metal screws with a 300 series stainless steel head and threads fused to hardened steel lead threads and self-drilling point. Stalgard GB coating provides a galvanic barrier. #2 self-drilling point can drill thicknesses up to .140". 5/16" hex drive. <br /><br />Bi-Flex fasteners provide unmatched corrosion resistance and high performance in a wide range of demanding applications, including aluminum, and are virtually immune to delayed embrittlement failures.