A no-lash nut assembly for installation on a threaded rod and including a lead nut, a trailing nut, a transition nut and a torsion spring. The decomposition may be accomplished by treating the polymeric precursor fibers with acid vapor from an aqueous acid solution at a temperature of less than 250\xb0 C. The block of calcium compound is preferably one prepared using an artificially synthesized calcium compound, most preferably a foamed calcium compound. The insertion groove is adapted to receive a surrounding wall of the plug and has a substantially quadrangular shape viewed from the front side. Characteristics may be determined and verified, and operation based on the outcome of such.