SHAFT: One-piece extruded 6063-T6 Aluminum Alloy tube treated to a T6 temper. GROUNDING: Provision; 3/8-16 Threaded Stud welded to inner shaft wall opposite Hand Hole. Flat Washer and Hex Nut provided. HAND HOLE: Reinforced 3? X 5? Hand Hole is located 18? above base. Cover and attachment hardware provided. HARDWARE: S304 Stainless Steel TOP CAP: Removable Top Cap provided with drill-mount poles.