The TB Wood's 1VP68138 1-3/8" Fixed Bore 1 Groove Variable Pitch Pulley 6.55" OD is engineered to provide precise control over belt tension and speed, addressing the challenges of maintaining optimal performance in variable speed applications. This pulley is designed to accommodate a range of belt types, including 3L, 4L, 5L, 5V, 5VX, A, AX, B, and BX, offering versatility for various industrial settings. Its fixed bore design ensures a secure fit on shafts with a 1-3/8" diameter, while the keyway size of 0.312" x 0.156" enhances stability and minimizes the risk of slippage during operation. Constructed from high-quality cast iron, the 1VP68138 pulley combines durability with efficient power transmission, effectively reducing maintenance needs and extending the service life of associated components. The pulley features a maximum pitch diameter of 6.02" for 3L belts, 6.55" for 4L/A belts, 6.61" for 5L/B belts, and 6.96" for 5V belts, providing flexibility to meet specific application requirements. Its outside diameter of 6.55" and length through bore of 1.91" contribute to its compact design, facilitating integration into systems with limited space. By selecting the TB Wood's 1VP68138 pulley, businesses can achieve enhanced operational efficiency, reduced downtime, and improved overall system performance.