This bolt-and-nut assembly secures the ploughshare or a wear component to the plough leg on a mounted or semi-mounted plough. The M12 thread passes through the component and into the threaded boss on the leg; the integrated nut locks the assembly against vibration loosening during operation. The two locating tabs on the bolt head prevent the fastener from rotating when the nut is torqued, eliminating the need for a second wrench on the underside. A loose or missing fastener allows the plough body to shift, causing uneven furrow depth and accelerated wear on the share point. On reinstallation, clean the threads and torque the nut to the specified value for the hardness class.