Unique web geometry, especially useful in portable drilling of stainless steel, titanium alloys, and other hard to drill materials. Application: Steel erection, mining, heavy construction. Used in a wide range of manufacturing plants, vehicle, railway and dockyard maintenance. Diameter: 0.390625" Decimal Equivalent: 0.3906" Flute Length: 3 3/4" Overall Length: 5 1/8"