Abstract: In a magnetic head (1) having a ring-like magnetic core (4) consisting of two core elements (9, 10) and having a terminating element (21) connected to the two core elements (9, 10) at the rear of the core elements (9, 10) by means of a connecting layer (23), the two core elements (9, 10) have a constant thickness and are without material recesses in their rear portion (8) and the connecting layer (23) between the two core elements (9,10) and the terminating element (21) consists of a layer having a high magnetic resistance, preferably of a non-magnetic material such as solder glass.

Abstract: In an arrangement (1) comprising a shaft and a part having a hub (57) mounted on the shaft and comprising at least one tubular portion to be clamped onto the shaft, and a clamping member, which can be mounted on said tubular member (72, 73) comprises three inwardly directed clamping zones which are equispaced at angles of 120.degree. from one another and which are each movable in a radial direction. The clamping member and its three clamping zones are situated at the same level perpendicular to the shaft and the clamping member is constructed to be elastically deformable in radial directions and in addition comprises three application zones for an expansion device (150), which application zones are also equispaced at angles of 120.degree. from one another and are each movable in a radial direction.