Drillco Chatterless Countersink, Imperial, Series: 3900E, 1/4 in Diameter Body, 2 in Overall Length, Round Shank, 1/4 in Shank Diameter, 6 Flutes, Right Hand Cutting Direction, 82? Included Angle, HSS, Bright. Drillco 39E116B 3900E Imperial Chatterless Countersink, 1/4 in dia Body, 1/4 in dia Shank, 6 Flutes, 82? Included, HSS