A nail is a hard metal or alloy that is pin-shaped and used to fasten materials such as wood and metal together. They come in a variety or lengths and thicknesses and are typically made of steel. Nails are often coated or galvanized to make them corrosion resistant. Nails have been used for centuries and their history dates all the way back to Biblical times. The one downside to nails is that eventually they rust and become useless. Why do nails rust? Read on to find out.
Why do Nails Rust?
Most nails are made of steel. Steel is an iron and carbon alloy that is used due to its strength and versatility. Nails rust because of the reaction of iron and oxygen. We have all seen the green patina that builds up on copper or bronze. This is result of the reaction of the metal with oxygen. The same thing happens when iron is exposed to oxygen, but instead of the green patina you get rust. The oxygen in the air cause the iron to corrode (break down). The rust is a more stable form of iron, when iron encounters oxygen, they release energy by combining with one another and sharing electrons. It requires energy for rust to become iron again and this is why the reaction does not occur in reverse. Once iron and oxygen have combined they stay that way. The higher the concentration of oxygen is in the nails environment the quicker the nail will rust. This is why nails that are exposed to water, particularly saltwater rust quickly.