double cut Rock drilling bucket with collar plate

Main application very dense sand and gravel, weak to medium hard rock (< 50 MPa)  up to coarse gravel  is recommended in uncased bores or for bigger diameters and for secant pile walls Features Kellybox 200 mm round shank chisel pilot bit RP4, cutting edge and collar plate with round shank chisels ventilation pipe wear protection: hard facing or wear strips