Ball Bearing Idler Sprocket Bore Diameter 3/4 in Chain Number 80 Sprocket Material Steel Number of Teeth 12 Outside Diameter 4.33 in Bearing Material Steel Bearing Type Ball Length through Bore 23/32 in Lubrication Not Required Maximum Radial Load at Speed 1061 lb @ 600 rpm 1262 lb @ 300 rpm 1660 lb @ 100 rpm 892 lb @ 1200 rpm 958 lb @ 900 rpm Pitch Diameter 3.864 in Sprocket Width 0.72 in Teeth Heat Treatment Hardened Teeth Tightener Shaft Required None