A brake (BR 2) for a guide rod (2) which is moved axially and/or in rotation, composed of a brake housing (1) which surrounds the guide rod (2), having a clamping jaw (3) which is arranged centrally in said brake housing and which is fixedly connected to the brake housing (1) and which, during braking, presses radially against a guide rod (2), and having an inner clamping cone (11) which is moved axially in the housing (1) by pressure-medium-actuated pistons (6, 6.1, 6.2, 6.n) and the axial movement of which is, by the interaction of the inner clamping cone (11) and clamping jaw cone (3.2), diverted radially with respect to the guide rod (2). To permit an increase of the brake force without increasing the outer diameter of the brake for this purpose, a plurality of pistons (6, 6.1, 6.2, 6.n) which are movable parallel to the central axis (A) are arranged one behind the other in the brake (BR 2), which pistons are operatively connected to one another such that the forces exerted on the individual pistons (6, 6.1, 6.2, 6.n) by the pressure medium are added.