Sanwa Doughnut Auger Series are unique system to rotate casing (steel tube) and auger flight at the same time each opposite direction either by two separate auger drive units or by one auger drive unit.
The former we call Doughnut Auger and the latter we call Mono-Doughnut Auger.
Selection depends job application. This series are able to apply for offshore jobs also. One of new application of this series is to remove or to cut obstacles underground such as old piles, existing concrete constructions, riprap layer of old wharf, etc with heavy-duty cutter bits on casing and auger head.