The Sag Rod is made available by us for use in the various commercial and industrial applications. The offered rod is a rod for preventing the sagging of an open-web steel joist that is used as a purlin with its depth at right angles to a roof slope. It usually requires pass through of the members it supports. This pass through allows take-up to be achieved with standard nuts and washers. There is no need for left hand thread on either end. The sag rod is used to provide alignment for these members for the attachment of the steel panels and to reduce their tendency to bend laterally and twist.