rock drilling products yn27c,yn27t,yn27 advantage:easy operation,time saving,labor saving,fast drilling, ... ~0.7 mmApplicationsThe Internal Combustion Rock Drill Type YN 27C (YN27T) has functions of drillhole, cleavage, bruising, tamping and chiseling. It ... construction, quarrying, national defence works, etc. Rock drill YN27,YN27C,YN27T