Abstract: An apparatus for welding a metal grating structure is characterized by a fixture for holding a metal grating in aligned relationship with a nosing and side plates therefor, and a plurality of welding guns for automatically welding the grating, side plates and nosing together into a unitary structure. The fixture includes mounting members for receiving and holding each of the metal grating, nosing and side plates, and for then bringing the same together into aligned relationship. The welding guns are normally positioned remote from the fixture to facilitate placement of the components thereon, and are automatically movable theretoward to effect a predetermined number of welds at selected positions between the components.