Attributes . 40 Chain; 18 Teeth; 1 Row of Teeth; Hardened Teeth; 3.136" Outside Dia; 2.879" Pitch Dia; B-Hub One Side; Rough Bore Mount; 1/2" Chain Pitch; ANSI Roller Chain Type; No Keyway; Stainless Steel Material; 1-1/2" Max Bore . Names