Although some references use an Overhung Load Rating to determine selection for an application, this is a static rating which neglects many factors that influence the lifetime of the unit.  Zero-Max uses a combination of dynamic load rating (bearing life estimate based on application details) and over 40-years of industry-leading experience to determine the fit for an application.  Strength of the input connection should also be considered in OHLA selection.
The estimated life calculation can be done by the factory with some basic application information including:
HP
Speed (rpm)
Type of load – fan, blower, pulley, etc.
If a pulley, the diameter of the pulley and the distance from the face of the OHLAs output pilot are critical
If an axial fan, the fan weight, and the amount of thrust load are critical.  If the thrust load is not known, this can be calculated if the diameter of the fan, the CFM air flow, and the static pressure are provided.
Mounting Orientation (horizontal; vertical, shaft-up, or vertical, shaft-down)
Hydraulic motor/pump part number and/or a catalog page for the motor/pump
It is recommended to contact Zero-Max with your application specifications so an accurate L10h bearing life and input connection strength can be evaluated. Zero-Max Engineering can offer customization options to improve OHLA life expectancy in many applications if a standard unit will not suffice.