helical piles, screw anchor, screw piles, round shaft helical piles, round lead helical pier, foundation repair, underpinning support helical anchor, helical brackets, new construction. For shaft material of helical piles, popular material is ASTM A252 Grade3 steel, ASTM A500 Grade B steel, 40Cr steel, C1020 steel, J55 steel etc. For helix, most of our customers choose ASTM A36 hot rolled plates. We do hot-dipped galvanization according to ASTM A153 standard. Shaft Size: 2 7/8 inch Tubular-0.203 inch wall,2 7/8 inch Tubular-0.262 inch wall, 3 1/2 inch Tubular-0.300 inch wall,4 1/2 inch Tubular-0.337 inch wall, Helix Blade: 8 inch , 10 inch , 12 inch and 14 inch in diameter with 3/8 inch , 1/2 inch thickness. Length: 3ft, 5ft, 7ft, 10ft and other lengths according to customers' demand. Finish: Plain, Hot Dipped Galvanized, Painted are available on your request.