What key size is this sprocket cut for and what size set screw is needed? What threading for the set screw? You need to have this info , otherwise I can't order.
A: If you scroll down to the dimensional information page and open that document there is a chart in the upper third of the page which lists the standard key sizes as well as set screw tapping for the bore size ranges. For 1-1/4" bore sprockets it states that the keyslot is 1/4"x1/8" and the hub is tapped for a 5/16" (to be read as 5/16"-18).