Abstract: A tightener for securing tire chains about industrial tires. The tightener includes a pair of block members that are threadably engaged by a draw bolt. The draw bolt includes a tool engaging surface that facilitates attachment of a tool to turn the draw bolt about its central axis and correspondingly move the block members axially toward or away from one another. A pair of non-extensible lengths of chain are connected to each block and extend outwardly to free ends that are adapted for connection to the side rail chain of an industrial tire chain. Therefore, the tightener may be mounted with the length of chain connected to the side rail chain and the blocks and draw bolt substantially centered on the tire axis. The draw bolt may then be rotated to bring the block members axially together, pulling inwardly on the side rail chains to tighten the tire chain about the tire periphery.