A metal safety rail for open floors of a building under construction includes a baseplate secured to a floor surface, a substantially vertical inner stanchion integrally joined to the baseplate, a substantially vertical outer stanchion slidably disposed over the inner stanchion, and at least one guard member secured to adjacent outer stanchions, whereby a safety rail is ultimately disposed about a peripheral portion of an open floor of a building under construction to prevent workers from falling from the open floor to the ground below.