The progressive miniaturisation of metallic micro parts comes along with high requirements concerning economical and qualitative aspects. An appropriate fabrication method for meeting these demands presents micro forming and blanking. Although these processes are well-established for producing small parts in big quantity further miniaturisation leads to challenges for example in the manufacturing of appropriate tools. One approach to overcome this problem is the application of microsystems technologies and materials for tools. In this study monocrystalline silicon is used as punch material for blanking of copper foils. Aiming at an increased tool life defined cutting edge radii based on numerical investigations were applied at the silicon punches. Experimental investigations in a special high-precision test rig for microblanking show a reduction of outbreaks at the cutting edge for bigger radii in comparison to sharp punches. This also results in a significant enhancement of tool life. Besides these wear investigations also a decrease of maximum punch forces could be observed for punches with rounded cutting edges. Furthermore, metallographic investigations of the workpieces showed no significant degradation of sheared edge quality at the copper foils for punches with defined small cutting edge radii.