Abstract: A clamp shank device designed particularly for attaching a chisel type of plowshare, cultivator blade, or the like to the draft frame of an agricultural implement includes a resiliently-biased clamping arrangement confining a shank member against lateral tipping movement but permitting it to ride up and over obstructions. The shank member is rectangular in cross-section and has a forward, horizontal, attachment portion rigidly held flatwise against the upper face of a rocker plate whose rearward end is beveled downwardly and forwardly to provide an upper pivot edge across the width of the plate. Such pivot edge is received by and extends along the vertex of a forwardly and downwardly facing angle included between the steps of a bottom-stepped rear wall of a supporting frame that is adapted to be attached to and beneath a tool-carrying member of the implement draft frame.