Heavy construction for industrial use. Manufactured from Douglas fir, morticed, tenoned, glued and wedged. Hinged to the back board and bolted through the stiles for extra strength. Treads at 250mm rise, pinned with ring shank nails and fitted with check blocks at intervals to prevent sideways movement. Tie rod are fitted at not more than 4 treads apart. All with varnished finish and all metal fittings are rustproofed.