6200 Picture Window – Lawson Windows & Doors CONSTRUCTION. Basic frame sections shall be 2-5/8” extruded aluminum alloy 6063. Corner of main frame shall be coped and to receive its mating extrusion, and joined mechanically by two sheet metal scr CONSTRUCTION. Basic frame sections shall be 2-5/8” extruded aluminum alloy 6063. Corner of main frame shall be coped and to receive its mating extrusion, and joined mechanically by two sheet metal screws.