Walter introduced the MN3 insert geometry designed for cost-effective machining of non-ferrous (ISO N) materials. The geometry is ideal for the medium machining of ISO N metals such as aluminum, copper, or brass alloys and for the fine finishing of small components made from steel, stainless-steel, and high-temperature alloys.

Positive with four cutting edges, it can be used on both sides, combining long tool life and high metal removal rates with greater cost-efficiency. The polished rake face improves chip removal, and the extremely sharp cutting edge creates a softer cutting action, important factors in the insert's positive reception by the market. The softer cutting action enables successful machining of unstable components and components with long overhangs.

This double-sided insert is a powerful expansion of the existing Walter portfolio for ISO N machining with positive geometries, the FN2 and MN2. Walter is launching the new indexable insert in two grades; WN10 a cost-effective, uncoated, and polished grade; and WNN10 with a wear resistant HIPIMS PVD coating, with an extremely smooth surface, and an optimized layer bonding.

MN3 is the first Walter geometry to have double the number of cutting edges while also being highly positive. The rake angle on the radius is 29°. Users benefit from improved chip breaking because of the highly positive cutting edge – even when working with "lead-free materials" like CuZn21Si3P. The surface roughness was also optimized, allowing for an increased tool life when working with materials that tend to stick with built-up edges. The negative basic shape with double the number of cutting edges increases productivity and cost-efficiency.