530 High Performance roller chain Available as an economical high quality QRS series solid roller chain as well as an extra Heavy Duty “Delta” self-lubricating version, which has specially formulated lubricant impregnated into the bushings. On both qualities all critical points are heat treated and shot peened for greater durability. Chains are pre-stretched at the factory to reduce initial stretch. The Heavy Duty “Delta” version comes in a true custom style nickel plated finish. QRS Series chain, 120 Links