SD Series High Pressure DTH Hammers/Button Bit for Drilling Equipment Yanggu Jinyou Tool Co., Ltd. Base Info Model NO.:good qualitySurface Treatment:PolishingManufacturing Process:StampingMaterial:Cast IronTransport Package:Wooden BoxSpecification:3 Inch to 20 InchOrigin:ChinaHS Code:8402200000 Description Pre:DTH Hammer Drill Button Bit/Drilling Tool From China Next:High Quality Impact Bed