<p>A mine roof bolt includes an elongated rod and a polymer coating layer. The elongated rod has a first end and a second end with a protruding portion extending radially outward from the elongated rod. The polymer coating layer covers at least a portion of the elongated rod between the first and second ends. The elongated rod is movable relative to the polymer coating layer in an axial direction. The elongated rod has a first position where the elongated rod has a predetermined axial position relative to the polymer coating layer and a second position where the elongated rod has a displaced axial position relative to the first position.</p>
