Abstract: A pillar used as part of a shoring, decking or scaffolding frame is made from length of aluminum extrusion having an octagonal periphery with a plurality of internal radial projections whose ends jointly define an unencumbered axial channel dimensioned to receive at either end, the threaded stem of height-adjustment screw-jacks, without need of any screw-jack-mounting sleeves or other screw-jack-centering and holding device.