Abstract: A soil auger for creating smooth-walled cylindrical holes in the earth is provided for use with a drill. The auger has a central rotational axis with a tubular body that is open at a bottom cutting end, and enclosed at a top end by a cap assembly. The cap assembly has a top wall and a bottom wall. The top and bottom walls have apertures aligned with the central rotational axis for receiving a shaft in alignment therewith, and for attachment to a drill. The distance between the top wall and bottom wall compared to the overall length of the assembled auger determines the minimum height of the cap assembly to minimize the rotational imbalance of the auger during use for a given body length. A method of manufacturing the auger is provided using precision cutting tools to create apertures in the body and to maintain concentricity of the auger components.

Abstract: A soil auger particularly useful for removing a quantity of soil as a plug is provided, and is particularly adapted for use with a portable electric drill. The auger body is substantially cylindrical with at least one open end and provides a balanced unit for use at high rotational speeds. A series of teeth at the lower margin of the auger are alternately inwardly and outwardly displaced from the plane of the cylinder. The teeth may extend completely around the lower margin or only a portion thereof. Offset apertures in the walls of the cylinder permit removal of the soil contained therein. A shaft is mounted at the end of the auger opposite the teeth and adapted to be coupled to a hand held electric drill. In operation, the soil auger enters the ground driven by the drill which rotates the auger. The teeth of the auger create a circular hole in the ground around a plug of soil, the plug of soil entering the interior of the auger body for subsequent removal.