The difference between malleable iron wing nuts and zinc-plated malleable iron wing nuts lies in their surface treatment. Malleable iron wing nuts have a plain finish and are suitable for applications where corrosion resistance is not a primary concern. On the other hand, zinc-plated malleable iron wing nuts undergo a zinc-plating process, providing a protective barrier against corrosion, making them ideal for environments where exposure to moisture or chemicals is expected. Additionally, the zinc plating gives them a shiny, silver appearance, enhancing their aesthetic appeal.