Universal head solid rivet specification (20470) made from 2117-T4 aluminum alloy (AD), with a diameter of 8/32 inch (1/4 inch) (8), and a length of 8/16 inch (1/2 inch) (-8). An alternate or variant of the MS20470AD8-8 rivet. United States Military Standard. Governed by the MS standard series, administered by Military Standards.