Instead of tearing or gouging, the BD Drill Head shears off rock in a shaving action. This eliminates strain on bits and lengthens their effective service life. It also reduces weight needed for rapid penetration and resultant possibility of bits balling up.

Step Drilling Pattern

The BD is precision manufactured to obtain maximum effectiveness from each cutting surface with minimum bit wear. This is accomplished by setting bits in a "step" pattern so that each cuts only a small portion of the hole.

An important plus feature is the twin-bit arrangement along the outer surface. If the sizing bit is damaged, the extra bit will cut in its place and maintain hole size without interrupting work.