Rexnord NS820-21T Sprocket

The Rexnord NS820-21T Sprocket is a molded split nylon sprocket from the NS820 table-top/mattop family, designed for FlatTop conveyor chains and quick maintenance in tabletop systems. It has 21 teeth and a pitch diameter of 129.3 mm with an outside diameter of 129.5 mm and a tooth width of 52.0 mm, delivering precise engagement with standard flat-top chains. Bore options cover common round shaft sizes such as 1.00 in, 1-1/4 in, 1-3/16 in, and 1-3/8 in, with bore configurations offering a single keyway (1KW) or both a keyway and setscrew (1KW1SS) in PA material, depending on the specific variant. For the 1.00 in bore variant (1KW_PA), hub width is 51.0 mm and hub diameter 60 mm; for a 25 mm bore variant the hub width is 58.5 mm, reflecting the bore-size–dependent hub geometry typical of NS820 sprockets. The NS820 line is explicitly marketed as Molded Split Sprockets for table-top conveyors, enabling installation without removing the chain and simplifying service in continuous-material-handling setups. An optional compatibility note indicates Rexnord’s steel chain series (812, 815, and related hinge configurations) can be considered for certain cross-range applications.