"5/8 CUP PLUG, OUTSIDE DIA- .636 MIN - .639 MAX, OVER HT, .240 MIN- .280 MAX, CROWN HT- .049 MIN - .075 MAX, STOCK THKNS .042 NOM +- 003, REC HOLE DIA, .629 MIN - .631 MAX. STAINLESS STEEL PLUGS MUST BE STAMPED WITH THE LETTER S. PLUGS WILL BE FURNISHED PLAIN, PLATED, OR COATED AS DESIGNATED BY PART NUMBER."