They screwed up making them look like machine parts. They should have made them look like tooling. Tungsten carbide cutting tools and inserts are almost the same density as gold. They are frequently coated in titanium nitride, which is gold-colored.
A shipping crate gets mislabeled. A box of "tungsten carbide" drill bits gets routed to a warehouse, then distributed out to various Harbor Freight locations.
People buy them, and they get dull and break upon use, and the people throw them out and swear they'll never buy Harbor Freight junk again.
I mean, recently someone found the mother of all software vulnerability attacks because their login took half a second longer than it should. Steel being 2.5x heavier than usual sounds like an easy spot compared to that.
Tungsten carbide and gold are about the same density. Tungsten carbide is about 3 times as dense as iron/steel. Steel is about 3 times as dense as aluminum.
If you're expecting a steel part and come across a gold (or carbide) one, you'll know it immediately, just as you'd know a steel part from an aluminum one.