AGMA – American Gear Manufacturing Association sets guidelines for gear products based on the application they are running.
A gearbox service factor is the output capacity of the gearbox to the potential output capacity. So if the reducer capacity is 10 lb-in of torque and you are only using 5lb-in then the service factor is 1.5 because you are only use half the capacity.
@GearboxKing I completely agree with you but there is a differentiation between gearbox service factor and then application service factor.
The gearbox service factor is: the reducer can handle 10 hp and you are only using 1/2 that input capacity by putting a 5HP motor on it. 2 service factor.
The application service factor is: The gearbox output torque capacity is 100 lb in but the application only requires 50 lb-in so therefore the service factor is 2.0