First coupling part and tool coupling

A tool coupling comprising:

• a first coupling part having a first body and a conical pin extending from the first body along a center axis to an end surface and having a decreasing diameter from the first body to the end surface;
• and
• a second coupling part, the first and second coupling part being formed to interact with each other, the second coupling part including a conical seat, which extends along a longitudinal axis of the second coupling part, the conical pin being insertable into the conical seat such that the center axis and the longitudinal axis coincide, the conical pin including a cavity having a bottom surface opposed to the end surface, the cavity extending axially along the center axis from the end surface to the bottom surface and having a number of first protuberances, the number of first protuberances being separated and arranged at a distance from each other along a circumferential direction with respect to the center axis and forming therebetween a corresponding number of first recesses, the number of first protuberances being arranged at a distance from the bottom surface and each forming a respective first contact surface facing the bottom surface,
• the second coupling part including a pull member having a corresponding number of second protuberances, the second protuberances being separated and arranged at a distance from each other along a circumferential direction with respect to the longitudinal axis by a corresponding number of second recesses, the second protuberances each forming a respective second contact surface, wherein the second contact surfaces being formed to abut and be pressed against a respective one of the first contact surfaces by the pull member, the first contact surfaces forming an acute angle with the center axis, and the second contact surfaces forming an acute angle with the longitudinal axis, wherein the acute angle of the first contact surfaces is configured to allow a force to be formed that is radially outwardly directed and acts on the conical pin, which force contributing to an outer surface of the conical pin abutting and being pressed against an conical inner surface of the seat, at least radially outside the protuberances and the first contact surfaces.