I calibrated the EDX tonight, the software uses a sample with aluminum and copper to create a spectrum and then figures out the offset and gain to get the peaks in the right place. With that done I zoomed into the little screw in the picture with the dime edge and did an acquisition. This is what I got and the analysis side says the screw is composed of the following:

Element Line Weight% K-Ratio Cnts/s Atomic%

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Al Ka 6.26 0.0115 90.84 13.78

Fe Ka 1.68 0.0206 77.55 1.79

Ni Ka 1.06 0.0130 39.00 1.08

Cu Ka 55.95 0.5566 1483.97 52.35

Zn Ka 31.62 0.3132 728.50 28.76

Sr La 1.91 0.0066 19.13 1.30

Mo La 1.51 0.0079 23.45 0.94

Total 99.99

This works out to be a brass with aluminum added. Adding aluminum increases the strength of brass and makes it more corrosion resistant. I did have to go into the setting to tell it that it was seeing Aluminum and not Bromine and Zinc and not Rhenium. There are several elements that overlap.