How to Make a Screw Jack

A baseplate, cap plate, top plate, nut, bolt and pipe are all the parts you need to make this easy-to-weld weight-bracing tool.

heavy duty nuts and bolts
Heavy-duty nuts and bolts come in various lengths and diameters, as this assortment shows. The center bolt has a curved top plate, for specialized uses. In the background, lengths of pipe are welded to base plates. 
DAVID E. JOHNSON