QD series hubs and bushings are also available from Lynx Products. Originally designed for sprocket and sheave applications, the QD series has also been used for conveyor pulley applications. The 3/4 ” taper per foot on the QD offers a higher mechanical advantage over steeper tapers, but also results in higher pre-stress to the end discs which can lead to premature end disc failure. The XT series’ steeper taper and greater number of bolts produce comparable clamping force to the QD, but with reduced end disc stress. Lynx Products’ QD series hubs and bushings are also manufactured from 1045 steel, and incorporate the same tightly controlled radial tolerances between keyways and mounting holes as the XT series.