All Hall Signs aluminum blanks are manufactured at our Bloomington facility per U.S. Bureau of Public Roads Standards. Our standard blanks have 3/8" holes for mounting and radius corners in accordance with the Federal Standard Highway Signs Manual. The aluminum substrate base for our aluminum sign blanks is chemically treated to add longer life and weather resistance. Reflective Aluminum Blanks are covered with material on one or both sides. Choose from three grades of reflective material in seven standard highway colors.
I recently purchased the 20"x9" flat street sign blanks in double sided, red, Diamond grade, Scotchlite, for use as a "CLOSED" indication on a chain-link gate across a railroad track. (It seems one of our engineers could not see that it was closed in early morning fog.) I generally specify Diamond Grade for all of our projects. I have never had a 3M film product fail when used in it's designed application and the Diamond Grade film has a significantly longer "useful life" than Engineering Grade or even Hi-Intensity in the hot, Florida sun. At 1,000 feet when illuminated by a locomotive headlight, these sign blanks appear to be "internally illuminated". The reflection is even visible in daylight. I've used Hall Signs for several custom projects as well, and find their prices very competitive, their shipping charges reasonable and they have also delivered when promised.