MP1200 Grade Milling Inserts

The MP1200 series from Mitsubishi Materials is three new PVD-coated carbide milling grades developed to improve process stability by directly addressing common milling failure mechanisms such as thermal cracking, notch wear, rake-face wear and cutting-edge chipping.

Central to the MP1200 series grades is the newly developed Gene-Tenax™ multilayer PVD coating, engineered with nano-scale control of the layer structure. Unlike conventional laminated PVD coatings, which are prone to crack initiation at layer boundaries, the Gene-Tenax coating suppresses crack propagation by optimizing layer thickness and interlayer adhesion. The coating architecture combines an Al-rich AlTiN-based layer to improve heat and wear resistance with an AlTiN composite functional layer designed to enhance oxidation resistance and reduce welding tendencies when machining stainless steels, heat-resistant and titanium alloys.

In addition to the development of the coating, a carbide substrate was specifically designed
for a wide range of milling applications. Cutting simulations were used to analyze edge load, temperature distribution and thermal cycling across different workpiece materials. Based on
these results, the MP1200 series is offered in three grades.

MP1220: focused on wear resistance in stable cutting conditions and is ideal for alloy steels.
MP1230: a balanced grade for general-purpose milling of steels and stainless steels.
MP1240: optimized for high fracture resistance in unstable or high-load cutting of steels through to titanium and heat resistant super alloys.

Performance testing on alloy steel (42CrMo4) demonstrated the effectiveness of this approach. In comparative evaluations, MP1220 achieved more than twice the fracture resistance of a conventional PVD-coated milling grade under high-load conditions, while also suppressing rake-face wear and thermal crack formation. Stable cutting was maintained over extended cutting lengths, reducing the risk of sudden insert failure.

A vast range of 20 different cutters can be equipped with the new grade, ranging from the popular AHX, ASX, AJX and BRP types through to VPX, VOX and WSX type cutters. This enables a multitude of milling applications such as face, shoulder, side, high-feed and multi-functional milling. The MP1200 series is positioned as a single-grade platform capable of machining steels, stainless steels, heat-resistant alloys, and titanium alloys with consistent performance and improved tool life predictability.