A scabbler bit comprises a carrier having a body 30 with a lower face 31 formed to provide bores 32 for receipt of scabbler tips 44. The body 30 has a central bore 33 for passage of a fixing shank 34. The bore 33 is enlarged at the lower face 31 to form a recess 35 to receive the head 36 of the shank 34. The opposite face of the body 30 is formed with a counterbore 37 to receive the piston 38, the shank 34 being retained in the piston by a pin 39. Thus, axial loads on the scabbler bit are transmitted to the piston 38 via shoulder 40 of the carrier bearing on end face 41 of the piston 38, while any sideways of twisting load is resisted by the wall of the counterbore 37 bearing on the side face 42 of the piston 38.