Success Story

Maraging Steel Machining Improvements Yield Processing Time Reduction by More Than 80%

Implemented State-of-the-Art Tooling and Programming Technologies

McNally Industries, Inc. of Grantsburg, Wis., is one of the world’s leading consumers of cobalt-strengthened maraging steel for use in defense-related products, including land combat weapon systems. While maraging steel has a low carbon content that makes it strong, malleable, and machinable, it was not known for its ability to hold a good cutting-edge using existing tooling. Significant machining time was required to achieve results that met tolerances.

McNally engineers identified the machining processes for three pockets and four grooves of a cannon breech for immediate improvement.

A NCDMM-led team of Alliance Partners Kennametal, Inc. and Mastercam, along with SECO/Carboloy and SIEM Tool, was awarded the effort to evaluate McNally’s operations for overall improvements in processes, tooling, and part quality.

Leveraging state-of-the-art tooling and programming technologies to improve the efficiency of machining operations

To attain the increase in machining throughput McNally desired without compromising adherence to the precise and tight tolerances, one of the first improvements made by the NCDMM team was to improve the length, rigidity, and robustness of the tooling to overcome the disadvantages of using a 40 taper machining center. Other changes to the machining operations included the addition of plunge milling, a TiAIN coated, four-fluted offset flute endmill, shrink-fit tooling, and a specially designed AlTiN coated solid carbide slot cutter.

With these optimizations, McNally was able to reduce processing time by more than 80% without compromising quality and planned to apply the learnings and solutions to other maraging steel components.