A universal joint includes first and second parts interconnected by a coupling element, and a coupling mechanism for detachably engaging tool attachments such as sockets. The disclosed coupling mechanisms include an engaging element and an actuating element. The engaging element can include a pin, and the pin can be oriented either obliquely or longitudinally in the drive stud of the universal joint. The actuating element can include a collar and a central portion that crosses the central longitudinal axis of the drive stud. The central portion can be offset along the longitudinal axis toward the coupling element, and the actuating element can be configured to extend into an aperture formed by the coupling element and the second part of the universal joint.