The round aluminum shaft of the PA1 series (straight or tapered) will be constructed of seamless extruded tube of 6063 Aluminum Alloy per the requirements of ASTM B221. The shaft assembly shall be full-length heat treated after base weld to produce a T6 temper. Four (4) bolt cast aluminum base flange of alloy 356-T6. Available in diameters of 4", 5", or 6" with heights up to 20 feet.