NRG sprockets are custom fabricated for use with its precision molded non-metallic collector chains. The following information provides a brief overview of NRG sprockets for H78 as well as 720 chains. For more information or for clarification, please feel free to call customer service or our local sales representative.    Optional Sprocket Features Chainsaver Rims   NRG sprockets are optionally available with Chainsaver Rims. The chain saver rim is essentially a flange located in a position that provides for even load distribution along the sidebars of the chain. Also, precision curved sidebar of NRG 720 chain provides for even more efficient load distribution.     Special Hubs   NRG drive sprockets can be supplied with an integral shear pin hub in "A" plate style for attachment to a separate overload protection device, such as a ball-detent torque limitor.   Shear pin hub sprockets are the simplest and most cost efficient of the overload protection devices, and are available in a variety of designs and materials to fit your needs. Hubs are available in Cast Iron as well as Nylon 6, for extremely corrosive environments. Please refer to your job drawings and catalog cuts for additional information.       Segmental Rim Sprockets   NRG sprockets are optionally available in segmental rim design. These sprockets are constructed such that the rim section of the sprocket, consisting of several segments, can be removed and reversed or replaced without removing and replacing the sprocket hub. This can make sprocket replacement less costly.   NRG segmental rim sprockets are available in a variety of hub materials and styles. Please contact NRG for your specific needs.