Can perform pre-boring of gravel and round stone layers with high N-values or rock bed, demolishing of existing structures, and efficient drilling of foundation work obstacles such as PC piles, H piles, pine piles, etc.
Also, a swivel device is incorporated into the reduction gear, and water or mortar, etc. can be filled.

A method using a bit and percussion hammer and air from an air compressor to strike and demolish with the tip of the bit edge according to the back-and-forth motion of pistons.