4. An In-House Foundry Makes All The Gold For Rolex Watches. Rolex makes their own gold. While they have a small handful of suppliers that send them steel (Rolex still works the steel in-house to make all the parts), all the gold and platinum is made in-house. 24k gold comes into Rolex and it is turned into 18k yellow, white, or Rolex’s Everose gold (their non-fading version of 18k rose gold).