The disclosure is generally directed to abrasive rotary tools capable of expanding into a substrate. Exemplary abrasive rotary tools include an expandable collet configured to expand an abrasive surface of the abrasive rotary tool. The expandable collet may be positioned proximate to a multi-planar edge of a substrate, such as a hole, and expanded into the edge to more fully and/or evenly contact the edge of the substrate. In this way, an abrasive rotary tool may more quickly and/or consistently abrade the edge.

A collet-type mechanism for releasably gripping either an external or internal target surface of a tubular workpiece includes a collet receiver defining a collet receiver contact surface configured as a curved lateral surface of a truncated right circular cone, and a segmented collet assembly comprising a plurality of collet segments. Each collet segment defines a workpiece engagement surface configured for gripping engagement with a workpiece target surface, and a collet segment contact surface configured for at least partial contacting engagement with the collet receiver contact surface. The collet segment contact surface may comprise two axially-contiguous regions, one of which corresponds to a curved lateral surface of either an oblique circular cylinder or a right circular cylinder, and the other of which corresponds to a curved lateral surface of a truncated right circular cone.

A collet-type mechanism for releasably gripping either an external or internal target surface of a tubular workpiece includes a collet receiver defining a collet receiver contact surface configured as a curved lateral surface of a truncated right circular cone, and a segmented collet assembly comprising a plurality of collet segments. Each collet segment defines a workpiece engagement surface configured for gripping engagement with a workpiece target surface, and a collet segment contact surface configured for at least partial contacting engagement with the collet receiver contact surface. The collet segment contact surface may comprise two axially-contiguous regions, one of which corresponds to a curved lateral surface of either an oblique circular cylinder or a right circular cylinder, and the other of which corresponds to a curved lateral surface of a truncated right circular cone.