When the strata conditions are unstable, Casing is required to be driven to overall depth to prevent hole's collapse.
It's called All Casing Method(Benito Method, Shaft Drilling).
To Drive the Casing and retract it after concreting, casing rotator is strongly recommended to use.
With its superior rotating torque and lifting force, the machine shows the best performance of driving and retracting the casing.
If it's used together with Hammer Grab, it shows the fast excavating speed with its big volume of the jaw and it is available for excavating gravels and boulders layer.