It should also be noted that if it is "sold" for any value at all, that isn't Scrap. That sale is computed for Gain or Loss on Disposition.

You are not Depreciating; that is "we used up the value over time."

You are Disposing.

Scrap is a perfect example: the metal itself likely brings in some money, when something is truly scrapped.

Then, "donating" has different rules than "using and depreciating" and "selling for residual value."