Abstract: A wearing part arrangement (1) provided with a holder (11) providing releasable attachment of a wearing part (12) by means of a socket-and-pin type quick-fit coupling, wherein the holder (11) comprises a pair of opposing first guide portions (1132) being arranged to face corresponding supporting faces (1221) provided on the wearing part (12), and a pair of second guide portions (1134) arranged to face corresponding top faces (1223) of the wearing part (12), wherein one of the pair of the opposing first guide portions (1132) and the corresponding side supporting faces (1221) of the wearing part (12) is provided with at least one elevation (1222), and the other one of the pair of the opposing first guide portions (1132) and the corresponding side supporting faces (1221) is provided with a corresponding recess (1135) arranged for receipt of the elevation (1222) when the wearing part (12) is in engagement with the holder (11).

Abstract: A wearing part arrangement (1) provided with a holder (11) providing releasable attachment of a wearing part (12) by means of a socket-and-pin type quick-fit coupling, wherein the holder (11) comprises a pair of opposing first guide portions (1132) being arranged to face corresponding supporting faces (1221) provided on the wearing part (12), and a pair of second guide portions (1134) arranged to face corresponding top faces (1223) of the wearing part (12), wherein one of the pair of the opposing first guide portions (1132) and the corresponding side supporting faces (1221) of the wearing part (12) is provided with at least one elevation (1222), and the other one of the pair of the opposing first guide portions (1132) and the corresponding side supporting faces (1221) is provided with a corresponding recess (1135) arranged for receipt of the elevation (1222) when the wearing part (12) is in engagement with the holder (11).

Abstract: A hole opener used in conjunction with drilling in at least one of boulder and rubble stone formations includes first and second sets of cutters. Each of the cutters of the first and second sets of cutters has cutter teeth thereon and further include a shaft. The hole opener also includes a tubular carrier body, a first device for fixing the first set of cutters to the tubular carrier body so that the first set of cutters is positioned in a common first lateral plane with respect to a longitudinal axis of the tubular carrier body, and second device for fixing the second set of cutters to the tubular carrier body so that the second set of cutters is located in a second lateral plane with respect to the longitudinal axis of the tubular carrier body and at an axial distance from the first set of cutters along the longitudinal axis.