The Ultra Tool 910 series solid carbide single-end countersink with an uncoated (bright) finish creates a 90-degree conical opening that accepts a flat-head fastener so it sits flush with the surface. The six flutes provide a smooth finish on hardened materials and are more wear resistant than countersinks with fewer flutes. Solid carbide is harder than high-speed or cobalt steel and provides longer tool life at higher speeds. The uncoated finish has no additional surface treatment or coating. The tool has a single cutting end and a round shank that accommodates most drill chucks.

Countersinks are fluted cutting tools that cut a conical or gradually widened opening for a hole into the surface of a workpiece, which provides a seat for a screw or rivet head. They are also used to create center holes for a machine center, deburr surfaces, and enlarging existing holes. The countersink's body diameter should be the same size or larger than what is being countersunk.

Ultra Tool manufactures reamers, grinding burs, drill bits, and other rotary cutting tools. The company, founded in 1972 and headquartered in Huntington Beach, CA, meets International Organization for Standardization (ISO) standard 9001:2000.