Highly positive with four cutting edges 30 August 2021

Walter AG has launched the new MN3 geometry indexable insert in two grades – a cost-effective, uncoated and polished grade, WN10, and in the grade WNN10, with a wear resistant HIPIMS PVD coating, extremely smooth surface and optimised layer bonding.

The polished rake face, for improved chip evacuation, and the extremely sharp cutting-edge, for a softer cutting action, of the new geometry are particularly important factors for the insert’s good performance. The double-sided insert is a useful expansion of the existing Walter portfolio for ISO N machining with the positive geometries FN2 and MN2.

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 degrees. It can be used both for the medium machining of non-ferrous metals and ISO N alloys – such as aluminium, copper or brass alloys – and for the fine finishing of small components made from steel and stainless steel materials or high temperature alloys.

Thanks to the highly positive cutting edge and chip nubs, users benefit from improved chip breaking – even when working with ‘lead-free materials’ such as CuZn21Si3P. The surface roughness has also been optimised, which allows for an increased tool life even when working with materials that have a tendency to stick (built-up edges). Finally, the negative basic shape with double the number of cutting edges increases productivity and cost-efficiency. 

Deputy Editor

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889


Having joined the magazine in 2012, Claire developed her knowledge of the industry through the numerous company visits, exhibitions and conferences she attended both in the UK and abroad.

Claire prides herself on keeping readers well informed and up to date with the latest industry news.