In the past, when machining deep, narrow cavities in molds, the considerable overhang of the cutting tool would substantially reduce overall rigidity, causing vibration during the process and degrading surface finish; in severe cases, this could lead to tool breakage or dimensional out‑of‑tolerance on the workpiece.

In addition, due to the geometric characteristics of deep fine grooves (small cutting width, large cutting depth), the chip removal space is affected, and chips are easy to accumulate in the groove, causing workpiece scratches, tool chipping and other problems. So many times, customers often choose relatively safe discharge machining to make.

Then for the pursuit of high efficiency, high quality OSG, the processing efficiency of discharge machining is too low, so in the tool design, the way of cutting, etc. have been improved, so that the deep fine groove of large overhang can also be processed stably by milling cutter.