Generally speaking, a 1½" (38-mm) attack hose can flow:

The flow rate of a 1½" (38-mm) attack hose is generally recognized to fall within the range of 60 to 125 gallons per minute (gpm). This range is based on standard operating procedures and empirical data regarding the performance of hoses of this size.

Hoses of this diameter are typically used in residential and light commercial firefighting situations, where the goal is to provide a manageable but effective amount of water to combat fires. The choice of 60 to 125 gpm reflects a balance between achieving effective fire suppression while maintaining the ability for firefighters to maneuver and handle the hose more easily.

Understanding the flow rate is crucial for firefighters, as it impacts tactics such as the ability to effectively suppress a fire, maintain sufficient pressure at the nozzle, and ensure adequate water supply without overwhelming the personnel handling the hose. The selected range aligns with these operational needs and allows firefighters to operate efficiently in various firefighting scenarios.