Reply to "Must use copper wire for track pins. What gauge please? What does "half-hardened" mean please?"

I would not use aluminum, copper is the way to go.

@Mannyrock posted:

Because I mixed different curve radius sections in a large curve, I can't close that curve up with my straight-run section unless I add a One-Inch section of 031 curve to the end of the last 10 inch 031 curve section.

Cut the full curve down a few inches and use a larger curve segment, then you can use normal pins.  It'll also probably line up better than a 1" piece of track.