Abstract: Scaffolding that has a high strength-to-weight ratio, and is light, well balanced and easy to carry, lift, and assemble. The decking cross member of scaffold frames according to the invention is placed at approximately forty percent (40%) of the height of the scaffold frame. Other structural members laterally connect the frame uprights to add strength and to balance the frame about the midportions of the uprights. This structure allows for quick and easy scaffolding assembly with a minimum of danger. A worker standing on the decking of a level of scaffolding can easily reach the top of the frame supporting the decking on which he is standing, which is approximately waist high, in order to assemble the next level of scaffolding. Location of the decking cross member also places the decking at approximately the same height as the cross bracing between frames, so that workers standing on the decking can work on adjacent vertical surfaces with minimum impairment of arm movement by cross braces.

Abstract: A clamping-type guard rail support having a post which is clamped in position by raising an opposing clamping arm attached to a threaded rod which is braced to prevent rotation of the rod and arm.