JA Series 7/8" Finished Bore QD Bushing For QD JA Series Sprockets, Pulleys, Sheaves. QD Bushing, Black Oxide over C45 Steel Finish Standard Keyway 3 - (10-24 x 1) Screws Torque Capacity (lb/in) 1,750 JA QD (Quick Detachable) bushings are precision-engineered components used for mounting pulleys, sprockets, and sheaves onto shafts in power transmission applications. They feature a split, tapered design that provides a secure, concentric grip while allowing for easy installation and removal. The JA size is one of the smaller options, typically fitting shafts of around 1/2” to 3/4” in diameter. Made from durable materials like cast iron or steel, JA QD bushings ensure reliable torque transmission and minimal shaft wear, making them ideal for industrial machinery, conveyor systems, and agricultural equipment.