84645 aka 2732976 is a Widia/GTD high performance 5/16-18 NC H5 2B, 3 Flute, EM-SS  Spiral Flute, Blind Holes, Blk.Oxide Coated, 2.72″oal, x .47″thread length x 1.13″reach x .318″shank, for Stainless Steels and other gummy materials.