A crank for an ice drill, which crank comprises a crank rod with an upper crank rod part and a lower crank rod part, and a coupling device, which is arranged to pivotally connect the upper crank rod part to the lower crank rod part so as to allow the upper crank rod part to be pivoted in relation to the lower crank rod part through the coupling device between an unfolded use position and a folded transport and storage position, the coupling device comprising: - a sleeve-shaped first coupling part, which is fixedly connected to the lower crank rod part and arranged with its longitudinal axis perpendicularly or at least essentially perpendicularly to the longitudinal axis of the lower crank rod part; - a second coupling part, which is fixedly connected to the upper crank rod part and rotatably received in the first coupling part; and - a locking mechanism, which is manoeuvrable between an unlocked position, in which rotation of the second coupling part in relation to the first coupling part is allowed, and a locking position, in which the second coupling part is prevented from being rotated in relation to the first coupling part, characterized in: - that the coupling device comprises a blocking member attached to the second coupling part and protruding radially therefrom, which blocking member is arranged to accompany the second coupling part during rotation and axial displacement thereof, this blocking member being arranged to be received in a groove in a first end of the first coupling part when the upper crank rod part is in said unfolded use position; and - that the locking mechanism by means of a manoeuvring member is manoeuvrable from its unlocked position to its locking position and vice verse when the upper crank rod part is in the unfolded use position with said blocking member received in said groove, the locking mechanism being arranged to prevent, in its locking position, mutual axial displacement between the second coupling part and the first coupling part so that the blocking member thereby will be retained in said groove while preventing mutual rotation between said coupling parts (20, 30), and arranged to allow, in its unlocked position, mutual axial displacement between the second coupling part and the first coupling part so that the blocking member thereby is allowed to leave said groove while allowing mutual rotation between said coupling parts (20, 30). - a sleeve-shaped first coupling part, which is fixedly connected to the lower crank rod part and arranged with its longitudinal axis perpendicularly or at least essentially perpendicularly to the longitudinal axis of the lower crank rod part; - a second coupling part, which is fixedly connected to the upper crank rod part and rotatably received in the first coupling part; and - a locking mechanism, which is manoeuvrable between an unlocked position, in which rotation of the second coupling part in relation to the first coupling part is allowed, and a locking position, in which the second coupling part is prevented from being rotated in relation to the first coupling part, - that the coupling device comprises a blocking member attached to the second coupling part and protruding radially therefrom, which blocking member is arranged to accompany the second coupling part during rotation and axial displacement thereof, this blocking member being arranged to be received in a groove in a first end of the first coupling part when the upper crank rod part is in said unfolded use position; and - that the locking mechanism by means of a manoeuvring member is manoeuvrable from its unlocked position to its locking position and vice verse when the upper crank rod part is in the unfolded use position with said blocking member received in said groove, the locking mechanism being arranged to prevent, in its locking position, mutual axial displacement between the second coupling part and the first coupling part so that the blocking member thereby will be retained in said groove while preventing mutual rotation between said coupling parts (20, 30), and arranged to allow, in its unlocked position, mutual axial displacement between the second coupling part and the first coupling part so that the blocking member thereby is allowed to leave said groove while allowing mutual rotation between said coupling parts (20, 30).