Ignoramus21381 wrote:
I have 625 tools of a certain kind. If I sell one per week, that means
that I will be selling them for the next 12 years. (scary thought)

This is the down side of large inventory.
They are made of steel and have dark finish (phosphate), but are not painted.

I am going to store them outdoors, in three rectangular plastic bins
with covers that snap over them, so that rain water does not
penetrate.

In addition, I placed desiccant bags in those bins.

Would you say that it is sufficient to prevent them from rusting for
12 years.
In MY climate, Missouri, not a CHANCE! Maybe in yours, not
sure. Every day when the sun comes up, the air heats up faster
than something solid, and moisture can condense on the parts.
If the bins are practically hermetic, then there might be a
chance. Otherwise, maybe putting them in giant zip-lock bags,
with the dessicant and a humidity indicator card sealed inside
might help. You can check the humidity card every few months to
spot the bags that are leaking. Otherwise, you need a
protective spray.

Jon