A taper bushed sprocket is a sprocket where a tapered bushing is bolted into the taper bore that is machined in the sprocket. When installed this bushing is compressed onto the shaft providing a tight grip. Taper bushed sprockets have a tapered bushing bolted into a taper bore with hex head set screws instead of bolts. Martin Single Pitch Roller Chain Sprocket, Taper Bushed Type B, 3.553 in Outside Dia, #35 Chain, 28 Teeth, 3/8 in Pitch, 3.349 in, 2-7/8 in Hub Dia, 1 in Length Through Bore, 1610 Taper Lock Bushing, Steel