Acrow props are a popular form of construction equipment commonly used as temporary support during repair works. The Acrow props are adjustable for height by a large diameter screw thread, formed on the outside of the tube itself. The screw thread provides a fine adjustment over a short range. A loose pin through a series of holes in the inner tube gives a wider range of coarse adjustment. Use of a screw thread also allows the props to be tightened when already in place, to adjust the load that each one bears.