The base code "20470AD5" specifies a universal head solid rivet (20470) made from 2117-T4 aluminum alloy (AD) with a shank diameter of 5/32 inch (5). The suffix "-7.5" indicates a rivet length of 15/32 inch. The prefix "MS" identifies the part as a Military Standard component, assigned by the United States Military Standard system. Governed by the MS standard series, administered by Military Standards.