Open-end wrench attachments allow lateral access for tightening bolts and sockets on pipe connections, hydraulic lines, and threaded rods. The automatic short release provides a clearly audible and perceptible click signal when the preselected torque is reached. It features high triggering accuracy according to DIN/ISO 6789, with a tolerance of +/- 3%. The attachment tools have an insert square (9 x 12 mm) for locking with a spring pin.