 High quality materials are characterized by increased wear resistance, high strength and hardness, abrasive wear resistance, heat and creep resistance. Due to these properties some materials are considered as hard to machine. This group of materials includes biocompatible materials used for manufacturing implants from commercially pure titanium TGR2, TGR5, nanostructured commercially pure titanium NTI and volume formed titanium alloy TNBTA. Materials were tested by milling operations with different cutting parameters and force of cutting monitoring. This article was authored by Dana Stancekova, Jan Semster, Josef Halbdek and others.