The invention relates to a rotor, particularly a rotating tool for machining workpieces while cutting. The rotor comprises a rotor base body (2) with locations (6), which are formed on the periphery thereof in an interspaced manner and which are suited for fitting the rotor with functional elements (7). The invention is characterized in that the rotor base body (2) is comprised of a first, radially outer base body element (3) and of a second radially inner base body element (4). When the rotor (1) is not rotating, a jointing pressure prevails along an encircling joint line (5), which is formed between both base body elements, and the radially inner base body element (4) is made of a material having a higher modulus of elasticity than that of the radially outer base body element (3).