Abstract: A clamping arrangement for the support of temporary guard rails of the kind used on balconies, shaft openings, porches and other building parts, and particularly for use during building construction. The clamping means includes a tubular upright post carrying means for the support of guard rails. The post is fixed on a frame of inverted L-shape. Adjustably mounted on a leg of the frame are two clamping bars constituting jaws of the clamp. Stops are provided on the leg of the frame and they act to locate one of the clamping bars at one or more positions on the leg of the frame, the other clamping bar being moved to a co-operative clamping relation with the first bar by means of an adjustable threaded rod extending through the tubular post.