The embedded, or Groundset, mount is the method of choice for mounting aluminum flagpoles at grade. Flagpole shafts so mounted have a higher wind speed rating than the same shafts base-plate mounted.
A FOUNDATION TUBE:
Fabricated from 16 ga. galvanized steel, with a steel base plate whose square dimension is at least the internal diameter of the sleeve plus 4''. A setting plate 6'' square shall be securely welded to the ground spike at least 6'' below the base plate. The ground spike shall be 3/4'' diameter, not less than 18'' long. 1. Provide spun aluminum collar, Type FC-11, finished to match flagpole shaft. Diameter shall be at least 1'' greater than diameter of sleeve.