During the cutting process on machine tools an important role is held by the subassembly performing the tool clamping. In case of boring and milling machines the tool must be automatically clamped and unclamped within a time as short as possible. This work is presenting a new solution for clamping and unclamping the tool that, compared to the usual solutions applied by the machine tool building companies, provides a high safety degree as well as low overall size. A version of this solution is presented as well, consisting of tool holder clamping from the inside.