We'll call the "Binding Bolt" the "Axle" and call the bolt which retains it the "Bolt"
Simply make the hole in your channel to clear the Axle at one side and the bolt at the other, the axle will insert through one side of the channel and sit against the other, the retaining bolt will tighten and retain the axle without pulling the channel together.
Use a chuck or collet chuck to hold the axle end still and to tighten the bolt, a little medium strength locktite on the bolt thread will ensure it does not work loose.