... smooth and steady, high strengthModel numberStandard or nonstandard (single duplex and triple)20A10-100, 40A10-100, 60A10-100, 80A10 ... normal, heat treatment, standard: NID,ANSINo.2 Machinery transmission sprocket:14B-2-20T, material:C45/A3, surface: chroming,heat ... treatment, standard: NID, ANSINo.3 Machinery transmission sprocket: 16B-1-36T, material: C45\A3, surface: black oxide ...