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.

Other enhancements include a wear-resistant and tough ultrafine-grain carbide substrate, a 27° helix with a shortened flute runout for effective chip evacuation when cutting a variety of materials, through-coolant for threads down to M4 and a multilayer TiCN coating that reportedly permits higher cutting speeds and longer tool life. The tools are also available uncoated and can produce threads from M3 to M16. The tools have an aggressive rake angle and can thread material as hard as 48 HRC.

In laboratory comparisons with similar tools, the company reported that the new TMC thread mill lasts 50 to 100 percent longer. For example, an automotive and racing company applied the tool to mill M4 threads 2 diameter deep in control arms made of 300-M steel, which has a tensile strength of 217,550 psi. With the TMC thread mill, the company achieved a 200-sfm cutting speed and 0.0007" feed per tooth and increased the number of threads cut during a set amount of time from 80 to 145—an 81 percent increase.

In another application, a contract manufacturer machining coupling flanges made of 6150 spring steel, which has a tensile strength of 152,280 psi, cut ½"-deep M10 threads with a TMC tool. Machining parameters were 220 sfm and a 0.0014" feed per tooth. The previous tool cut 120 threads during a set amount of time compared to almost 550 threads for the TMC.

The latest version of the company's TEC-CSS tool selection and cutting date software, Version 10.3, contains optimized values for the TMC thread mill with countersink. The online software is available free of charge and recommends a tool based on the application, workpiece material and its hardness. "It lets you know what tools can be used as well as the speeds and feeds, estimated tool life and estimated cost per part based on your hourly shop rate," Hemmerling said. "We launch two updates per year to coincide with new product introductions."