Roller chain is used to transfer rotational forces from one shaft to another on agricultural machinery. If the chain breaks or is too tight or loose, a link must be added or removed. This is done by loosening the removable master link, modifying the chain length, reinstalling the chain so it's stretched tight around the sprockets, then replacing the master link. San Pierre, IN, farmer Louis Smolek has made a Roller Chain Assembly Tool that allows him, with one hand, to hold the loose ends of the chain together. The device consists of a stretch spring with a hook fastened to each end. To use it, the spring is first hooked to one end of the broken chain, then stretched to hook to the other end. The chain ends lay on the top-side of the spring to keep them in line while Smolek uses his one hand to insert the master link for connecting the chain ends. (Note: An alternative to this idea might be using wide-jaw locking pliers to bring the chain ends together. The jaws can be ground to fit any size or type of chain.)