Thank you all. The hex key was smaller than my smallest 1/16" and the hardware stores didn't have it alone or in sets. I actually had a couple hex keys much smaller in my kit.
Now that I know what size I am looking for, I will be able to get one at least on order. SAE 0.050 is the smallest conventional size I believe.
FYI, I failed at home depot, radio shack and True hardware, but the hardware store will order it for me.
Thanks to all again.
Greg