MA Ford 64100004, UniFlute Countersink Set 100-Deg., 4 PC. 1/4, 1/2, 3/4, 1, Diameter: , Shank Diameter: , Overall Length: , Included Angle Deg.: 100, Base Material: HSS, Number of Flutes: 1, MPN: 64100004, PKG QTY: 1 PC Description: MA Ford Series 61 HSS Uniflute Countersink. The original single flute countersink designed for general purpose countersinking, chamfering or deburring.