hexagonal rode Hollow Electric Hammer Drill used for cement wall,brick,stone. made by 40CR and YG8c carbide hexagonal rode Hollow Electric Hammer Drillused for cement wall,brick,stone.made by 40CR and YG8c carbideconnecting rode type:SDS-plus round/square shank, hexagon shank, SDS-max round shank,spline shank hexagonal rode Hollow Electric Hammer Drill