Made in USA 152-3-100-.1590 2-1/2" Overall Length, 1/2" Head Diam, 3 Flute, 100° Incl Angle, Integral Pilot, Adjustable Stop Countersink, 1/4-28 Straight Threaded Shank, 1-3/4" Shank Len, 3/16" Shank Diam, 0.159" Pilot Diam, #21 Pilot Diam, High Speed Steel. Priced and sold as each (1).