... and enhanced drill rock-breaking effect. ·Based on CZ-6A type, the CZ-6B type through great technic improvement made it more ... -diameter foundation pile and deep shaft sinking. ·The CZ-6C type derived from CZ-6B, with greater effect, greater strength products, has ... made tremendous improvement to the CZ-6B spindle and impact beams. ·Concrete Cast-in-place Pipe ...