A mount for connecting a welding gun to a welding robot's arm. An articulated joint is provided between two rigid elements of the mount. The joint includes a sleeve securable to a first element. A first bore is provided on the second element. The sleeve is inserted into the bore. The bore's inner diameter and the sleeve's outer diameter allow the second element to turn with the first bore relative to the sleeve. An expansion element provided in the interior of the sleeve is displaceable in the longitudinal direction of the sleeve. The expansion element has a central opening through which a tensioning bolt is passed. The bolt threadably engages a support element causing expansion of the sleeve, thereby causing the sleeve to seize around the circumference thereof in the bore. The expansion and seizing of the sleeve is neutralized by a release and stop.