Fixed-bore cast-iron variable-pitch V-belt pulleys have a finished bore, or center hole, that is machined to a set diameter to insert a shaft of the same size. They are ready to install with machined keyways and/or set screws to secure the shaft and prevent slipping. They are constructed of cast iron which has good wear resistance and absorbs heat.

Fixed-bore die-cast variable-pitch V-belt pulleys have a finished bore, or center hole, that is machined to a set diameter to insert a shaft of the same size. They are ready to install with machined keyways and/or set screws to secure the shaft and prevent slipping. These zinc die-cast pulleys are non-corrosive, lightweight, impact-resistant, and non-toxic. They are suitable for light duty applications such as fans and blowers in HVAC applications.