Shaft Size: 2 7/8 inch Tubular-0.203 inch wall,2 7/8 inch Tubular-0.262 inch wall, Shaft material: Seamless high tensile pipe, popular material is ASTM A252 Grade3 steel, ASTM A500 Grade B steel, 40Cr steel, C1020 steel, etc. Helices material: ASTM A36 Hot rolled plate. Corrosion protection conform to ASTM A153 standard for hot dipped zinc coating. Leading edge of Helices beveled 45 degrees. Greater Section Modulus Strength to resist Twisting and Deflection. Greater Load Capacities. For North American customers, door to door service is available. We have our own factory in China, can manufacture the helical piles according to your detailed specifications. All kinds of helical piles for deep foundation are available according to customers' demand. Such as round shaft helical piles, square bar shaft helical piles, push piers, helical brackets, etc.