The entire image of King Nebuchadnezzar's dream recorded in Daniel 2, was metal EXCEPT for miry potter's clay in the feet and toes. Daniel clearly shows that the different metals represented different KINGDOMS.

And after you another kingdom inferior to yours will arise, and another third kingdom of bronze that will rule over the whole earth. Daniel 2:39

Metal is HARD, as the hardness of unrepentant hearts.

And when he had looked round about on them with anger, being grieved for the hardness of their hearts, he saith unto the man, Stretch forth thine hand. And he stretched it out: and his hand was restored whole as the other. Mark 3:5

Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen. Mark 16:14

The hard metals represent GOVERNMENTS (King James translation calls them "Kingdoms"). Governments are HARD, unbending and unforgiving. All governments rule by force and coercion. If you disagree, read "The Gulag Archipelago" by Aleksandr Solzhenitsyn. Oh, but that was the USSR! "MY" country isn't like that! Think so? Try breaking the rules or going against any government; force and violence will rain down upon you. The further the government is from God, the harder it is.

The head, as gold, is the most precious and softest metal. Going down the image, the metals become less precious (more base) and harder... silver, bronze and finally iron.

Iron, is the least precious (not a precious metal at all) and most hard.

... forasmuch as iron breaketh in pieces and subdueth all things: and as iron that breaketh all these, shall it break in pieces and bruise. Daniel 2:40

There is no doubt of the intent of this dream in describing governments as hard and violent against people. Governments use violence (HARD force) and coercion to enFORCE their wills. Bodies are left bruised (or dead).

Governments are NOT soft (forgiving, impressionable, yielding) like miry clay.