The paper presents the results of the cutting forces research (F f , F p , F c ) when machining of sintered carbides WC-Co (25 % Co) with tools made of polycrystalline diamond PCD. Inserts with three different nose radii r ε were used during the study. Each cutting test was carried out on the distance 54 mm at the constant depth of cut 0.2 mm. The biggest increase of passive cutting force component F p was indicated. In addition, the mathematical models for cutting force value prediction as the cutting path increases are presented. The paper presents also the algorithm of optimization and control of the super hard materials turning process.