In choosing a straight bit for any application, always select one with the shortest cutting edges and the shortest overall length that will reach the required CUT depth. Excessive length intensifies deflection and vibration, which degrade cut quality and Lead to tool breakage. A single-flute bit should be used where cut speed is more important than cut finish. Making one cut per revolution is faster than making two or three. Improved chip clearance is possible with a single flute configuration. The result: fast cuts, #45104, diameter (D): 1/4, cutting height (B): 1/2, shank (D): 1/4, overall length (L): 2, flutes: 1, 45104 carbide Tipped straight plunge single flute high production 1/4 dia x 1/2 x 1/4 inch shank.