MA Ford 61B037506, 3/8 HSS UniFlute Countersink,120 Deg, Blaze Coated, Diameter: 3/8, Shank Diameter: 1/4, Overall Length: 2, Included Angle Degree: 120, Base Material: HSS, Number of Flutes: 1, MPN: 61B037506, 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.