Cutting mechanisms and the cutting force are the focus of this article. The cutting force can be determined theoretically or mathematically by statistical analysis. In this work, the cutting speed was compared when changing the diameter of the test wood and when using the three types of angular geometry of delimbing knives. Experimental measurements were conducted on a self-designed experimental pneumatic stand. Empirical relationships and values from the scientific literature were used to determine the input parameters. Based on a regression analysis, conclusions were drawn relative to factors affecting the process of delimbing. The angular geometry of the delimbing knife plays a significant role in the delimbing process. The thicker the knife, the higher the energy consumption in the cutting process and the poorer the quality of the cutting surface of the wood. The quality of chipless separation timber was found to depend on the cutting speed, and the optimal speed was 2.0 m s-1.