Standard MX system tools feature insert widths between 0.8 and 3.25 mm for cutting depths up to 6 mm, though Walter can provide special sizes and designs – grooving with chamfer, for example – on request via the Walter Xpress service. Walter Cut GX34 has grooving inserts with widths of 3 or 4 mm for cutting depths up to 33 mm.
In developing the tools, Walter engineers say they have successfully overcome a range of important ‘accepted weakness’ with standard grooving tools, including poor chip breaking, chip removal, cooling and securing of the indexable inserts – which is often awkward, imprecise and insufficient.
Parting-off or deep grooving is widely considered a particularly difficult process and such applications are generally performed with cutting values that are too low, to avoid tool breakage or other problems. According to Walter, the weaknesses have also been eliminated with the new MX and GX systems.
MX tools offers a new approach to clamping, which Walter says is more user friendly and reliable. The tangentially clamped insert aligns itself independently and accurately in the machining direction, while a dowel pin in the insert seat ensures precise and secure fixing. Furthermore, inserts cannot be installed incorrectly and are easily changed. Unused cutting edges are protected in the holder, and the same insert type is suitable for both right and left tool holders.
The system’s potential was demonstrated in a tool life test in series production on a Swiss-type automatic lathe, where stainless steel pipes with an outer diameter of 5 mm were parted-off with inserts featuring a cutting edge of 1 mm. Walter’s Cut MX system more than tripled tool life compared with the former method.
High stability and process reliability are also characteristics of the GX34 system. A machining test at a customer that supplies nitrided steel drive shafts with diameters up to 60 mm saw GX34 extend tool life by 100%, while machining feeds increased by 30% thanks to the system’s stability, which minimised machining vibration.
All Walter Cut tools feature 10-80 bar precision cooling that is integrated into the tool holders, with coolant directed into the cutting zone for optimum cooling and high productivity. For instance, on ISO-S materials, cutting speeds can be increased by a factor of two while maintaining tool life. The grooving tools for small applications operate with a large coolant outlet.
Both the GX24 and latest GX34 tools feature two coolant outlets. Manual alignment of the nozzles is not required since the system cools the rake and flank faces simultaneously, with the second coolant jet aimed directly at the flank face. This precision cooling also has a positive effect on chip formation, with chips breaking in a controlled manner so that they are relatively short. Furthermore, with two jets of coolant ensuring a constant film of lubricant, chips can be transported out of the groove with less friction – resulting in high process reliability and surface quality.