Patent ID: 7806204

Claim:
A drill rod configured to be used for sonic drilling operations, the drill rod comprising: a rigid cylindrical body having an interior surface and an exterior surface; and a helical feature and a corresponding helical channel on the exterior surface of the cylindrical body, wherein: the helical feature has a first width and a thickness, the first width being defined by a distance the helical feature extends axially along the cylindrical body between portions of the helical channel, and the thickness being defined by a distance the helical feature extends radially outward from the cylindrical body, a ratio of the first width to the thickness is about 3:1 or greater, the helical channel has a second width defined by a distance the helical channel extends axially along the cylindrical body between portions of the helical feature, and the helical channel has a uniform depth, the second width is greater than the first width, and the helical feature and corresponding helical channel are configured for moving material displaced during a drilling operation in an axial direction away from one end of the drill rod to the other.