Sprockets, #40, 11mm bore?

justone:
The 5/8" bore sprocket would already have a keyway so there is no need for an arbor press or keyway broach. The hacksaw was just to remove the part of the sleeve where the key would be,like turning a "O" cross section into a "C" cross section .

Whoops my bad; I misunderstood what you meant. Turns out we were both saying the same thing.