Chicago Die Castng 450A Single V Grooved Pulley, 4-1/2" x 5/8", Pitch Dia.=4.25
For A belts, pulleys from 2'' to 12'' have keyways except 3/8'' and 1/2'' bores and 3/4'' bores in pulleys less than 4'' in diameter, All pulleys are with slotted headless set screws