Number on item that I cannot seem to cross G0 11 12 021, 60026769, 27FM-06-071F

It appears to be stainless steel.  I cannot determine manufacturer or any other pertinent information.

See photos for detail and condition.  Includes only what is pictured.

The following information is from my own observations and not based on technical specs.

Chain Number - 40

Chain Pitch - 0.500"

Outside Diameter 3.55"

Hub Diameter - 2.36"

Length Through Bore - 1.177"

Keyway Width - 0.39"

Bore Diameter - 1.258"

Does not include setscrew