Specifications include, but are not limited to: Blank Aluminum, 24 Inch X 18 Inch X 0.100 Inch, 1-1/2 Inch Radius, No Holes, SPECIFICATIONS: 1. All aluminum blanks and aluminum sheets shall conform to the requirements of ASTM B209 for Alloy 5052-H38 or 6061-T6. 2. Each size specified shall consist of a single piece. All edges shall be free of burrs. 3. All sign blanks and aluminum sheets shall be finished on both sides with a chromate conversion coating in accordance with ASTM B449, Class 2. The treatment shall produce a uniform coating tightly adherent to the metal, showing no dusting of the coating surface, and having a color within the range of silvery iridescent to pale yellow. 4. All circles, U.S. cut-out shields, and interstate shields shall be die-cut so they will be accurately cut to a uniform size and shape; Blank Aluminum, 30 Inch Octagon X 0.100 Inch, No Radius, No Holes, Blank Aluminum, 30 Inch X 24 Inch X 0.100 Inch, 1-1/2 Inch Radius, No Holes.