The Shaft 36/48" Model - 1X7-5/8 (Part No. 0411-2110) is a replacement cold rolled steel shaft designed for 36" and 48" PolarCool belt drive evaporative cooling fans equipped with flange bearing internal supports. Precision-cut to length with keyways machined for secure connection of motor and propeller pulleys, this shaft delivers reliable power transmission and ensures smooth, efficient operation in warehouse cooling, outdoor cooling systems, and industrial air coolers. Compatible with flange bearings (SKU 6403-1115 and 6403-1114). Requires two shear keys (SKU 1019-2417) for proper installation.