Scaffold base jacks are made to fit standard scaffold tube, typically 48.3 mm outside diameter, with the spindle inserting into the tube foot. The threaded rod is commonly around 34–38 mm diameter, with adjustment travel of roughly 300 to 600 mm depending on the model.

Scaffold base jacks are usually hot-dip galvanised or zinc-plated steel, giving corrosion resistance for repeated outdoor and site use. The base plate is welded solid steel, and the coarse thread is designed to shed dirt and keep turning freely in wet or muddy conditions.

Insert the spindle into the base of the scaffold standard, stand it on a sole board, and turn the adjusting nut to raise each leg until the frame is level. Keep the extension within the maximum safe travel marked on the jack and check the base plate sits flat and fully supported.

A scaffold base jack's safe working load depends on its steel grade, thread size and extension height, with capacity reducing as the jack is wound higher. GeZu Impex lists thread diameter, plate size and maximum extension per model so you can match the jack to the scaffold's load and tube size.