To thread a hole and countersink it in one operation, Walter USA LLC, Waukesha, Wis., (www.walter-tools.com/us) introduced a new version of the Prototyp TMC thread mill with a 90° countersink. "A lot of times it's cost-prohibitive to order a step drill, for example, or have a separate countersinking operation," said Mark Hemmerling, Walter's director of marketing.