Boston Gear F221S-PH-4-B5-H1 Gear Reducer

Boston Gear F221S-PH-4-B5-H1 Gear Reducer is a 200 Series Optimount Helical Gear Speed Reducer designed for shaft-mount installation. It provides a 4:1 reduction ratio, is rated for up to 1 hp input, and yields an output speed of about 431 rpm when fed with 1,750 rpm input, delivering roughly 289 in-lb of torque. This model is part of the Boston Gear family now under Altra Industrial Motion, combining the space-efficient shaft-mount format with the smooth performance of a helical gear train for reliable speed reduction in compact layouts. With its compact form and proven efficiency, the F221S-PH-4-B5-H1 is suitable for light-duty automation tasks where precise speed control and predictable torque transfer are essential.