Crank shaft pulley on 1993 Subaru Impreza

I replace the crank shaft pulley and keyway about a month later
the pulley be came lose the key way broke in half . Just bought
a used pulley and a new keyway

Asked by for the 1993 Subaru Impreza
it has to be torqued to 120 lbs. filaure to get this torque will result in the pulley coming loose and you have the end result.