The chopper knifes with a milled cutting edge demonstrated on a test rig, that a doubling of service life by variation of the production technology is feasible. The knifes with inserted cemented carbide have the potential for application in more than one harvesting campaign. The wear on the test rig was only 6 % compared to the wear of a serial knife. Practical tests have to demonstrate the behaviour of the cemented carbide against foreign substances. A special design has to be selected to save the cemented carbide blade. High hardness of the surface can be reached with the chosen final treatment technologies, but the thickness of the layer is low. Due to the abrasive wear the surface layer will be removed very fast and so an increase in service time can not be realized.With the test rig a method was applied, were the progress of wear can be represented in fast motion. Tests in practical conditions have to confirm the progress of wear.