... hydraulic rock drill is a new generation drilling equipmentsof our factory ,which takes more than 18 year careful development. And obtained ... stability control, low noise,simple,reliable, easy maintenance, flexible and mobile etc. The YYT28 is made for general excavations,quarrying ... The YYT28 can use water flushing or air flushing.YYT28 is a hydraulic rock drill to drill diameter 32mm(1¼”) to 50mm(2”) ...