threaded ends shall pass through framing girts and be secured at top and bottom by nuts welded on after assembly. 7-07. GRILLES: Location "B™ Grilled openings at Building No. 204, shall be of sizes to fit openings shown. Grilles shall be constructed of flattened expanded aluminum diamond mesh with opening size approximately 1 inch by 2-3/4 inches equal to expanded aluminum as manufactured by the United States Gypeun Company. Mesh strands shall have a thickness of .080 inches and shall be .194 inches wide. aluminum "U" edging. Mesh shall be welded to 1 inch Grilles shall be arranged to slide vertically in the openings. 7-08. BINS: Mesh bins at Building No. 302, Location "B", shall be constructed of flattened expanded aluminum equal to those specified in paragraph 7-07 preceeding, except that mesh shall be nominal 1/2 inch diamond mesh. Mesh shall be welded to aluminum as frames as detailed. 7-09. PIPE RAILS: Pipe rails shall be provided as indicated and shall be fabricated of aluminum alloy pipe unless otherwise directed by the Engineer. Railings shall be of design, materials and anchorage as detailed on the drawings; shall be of welded construction, and shall have an alumilite finish. Discolorations due to welding shall be touched up with aluminum paint. 7-10. LADDERS: Ladders shall be furnished and installed where indicated on the drawings. Ladders shall be of aluminum construction unless otherwise specified consisting of round rod rungs let into and welded in rectangular bar stringers. Details of construction and anchorage are indicated on the drawings