Patent ID: 7374375

Claim:
A shank of a working tool ( 2 ) that at least one of rotates about an axis (A) and is blow-driven at least partially along the axis (A), the shank ( 1 ) extending along the axis (A) with a maximal guide diameter (D) and comprising at least two, arranged opposite each other, locking grooves ( 5 a , 5 b ) each having a locking shoulder ( 11 ) provided at an axial locking end ( 3 ) and spaced from a free end surface ( 4 ) of the shank ( 1 ), and an end shoulder ( 12 ) axially spaced from the locking shoulder ( 11 ) in a direction of a working tool-side end of the shank ( 1 ) and spaced from the axial locking end ( 3 ) of at least one of the locking grooves ( 5 a , 5 b ) by a length (L) amounting at least to three times of the guide diameter (D); and at least two entraining grooves ( 6 a , 6 b ) mutually tangentially offset with respect to the locking grooves ( 5 a , 5 b ) and opening toward the free end surface ( 4 ), the at least two entraining grooves ( 6 a , 6 b ) having a tangential groove width (B) and at least one tangential, force application surface ( 7 ) extending over a contact length (K); wherein the end shoulder ( 12 ) is axially spaced from a working tool-side end ( 14 ) of a respective entraining groove ( 6 a , 6 b ) in the direction of the working tool-side end of the shank ( 1 ) at least by 1.5 times of the guide diameter (D).