Some results of the research on the performance of various diamond abrasive wheels for grinding of carbide knives are presented in the paper. The diamond wheels designed with metal coated and aggregated grains with organic bonds were used. The studies were performed at two levels of intensified, multi-pass sharpening TC (tungsten carbide) knives type K20, the part of a cutter head for longitudinal flat milling of solid wood and wood-based materials. The obtained results were analysed and relevant conclusions and recommendations were made. The process of sharpening carbide tools and its optimization can be better understood this way.