Why are Square Pole Adapters sometimes needed?
Square Pole Adapters, also known as Adaptor Shims, are used on the back of the D3 and Metro Main Castings to fit odd-shaped fluted poles or on the wide flat face of square poles where that face is over 5" wide. The extra space created between the back of the main castings and the pole face allows more banding tension onto the casting creating a very tight installation. Of course, these are not needed if bolting on to any size square pole. If the flat face is too wide and the shims are not used, the casting would tend to slip around under the banding and the installation would eventually work its way loose and fail.
