Our standard auger pinning pipe is 2.875" O.D. schedule 80 grade steel threaded pipe with 1" continuous flight (5.375 O.D.) and 4ft or 5ft lengths. It has been tested to support weights of over 100,000 lbs. This pier is perfect for pre-construction pinning and for drilling through high blow count layers of soil, such as shallow weathered rock layers or clay based soils. The flytes are robotically/machine welded for consistent weld penetration. Galvanization or powder coating is also available on all auger underpinning pipe.