Fabrication is the process used to manufacture steelwork components that will, when assembled and joined, form a complete frame. The frame generally uses readily available standard sections that are purchased from the steelmaker or steel stockholder, together with such items as protective coatings and bolts from other specialist suppliers.
Steel structures are often taken for granted. After all, they are made of reliably strong steel and are a common industrial building block. But if you stop and think about it, that reliability has more do with the integrity of the fabricator than that of the steel. It truly is more about the integrity of the engineered design loads, and the integrity of the welded joints, and the integrity of the weld inspection, and even more so the integrity of the company that backs them all up. All these have more to do with the integrity of the structural weldment than does the integral strength of the steel.