Our heavy duty cast aluminum IronRidge Top Caps secure quickly and easily to galvanized schedule 40 pipe (ASTM A53 Grade B) or mechanical tubing (i.e. Allied Flo-Coat, Gatorshield, Gatorshield-Plus) piers with with 2 set screws. Available in sizes that fit either 2-inch or 3-inch steel pipe and mechanical tubing, the top cap supports cross pipes with U-bolt hardware. The top caps are manufactured using cast aluminum ALMAG 535 and come with a mill finish. As a reminder, the substructure pipe and mechanical tubing are not included.