Mitsubishi Materials has expanded its AXD4000 series of milling cutters with GM breakers in MP9120 and TF15 grades. The GM breakers are offered in 0.4- to 5.0-mm radii and are designed to increase fracture resistance. The wiper effect of the minor cutting edge is said to improve surface finishes. The MP9120 grade features an accumulated AL-Ti-Cr-N-based PVD coating over the cemented-carbide substrate, providing toughness, a low coefficient of friction, resistance to heat and welding wear. The multi-layering of the coating prevents cracks from penetrating through to the substrate, the company says. The MP 9120 grade is well-suited for machining titanium alloys and high-silicon-content aluminum alloys, while the TF15 is suitable for aluminum alloys.