Though both materials are steel, galvanized steel and stainless steel are very different materials that have a variety of applications. Knowing the difference is important, especially when given the choice of which material to use when tackling a home improvement or construction project.
What is Galvanized Steel?
Galvanized steel is steel that is coated in a thin layer of zinc to help prevent corrosion. The zinc may be applied to the steel through a process of hot-dipping or electrogalvanizing.
Hot-dipped steel is steel that is dipped into a hot bath of liquid zinc. It is then removed and allowed to dry. The zinc coating adheres to the steel as it cools, creating galvanized steel.
Electrogalvanizing is accomplished by submerging steel in an electrolyte bath. When the steel is removed the coating hardens, creating a thinner, bonded layer of zinc.
Uses for Galvanized Steel
Galvanized steel is a common material for home construction projects. It is often used in framing homes. Nails, nuts and bolts are made from galvanized steel. It is also a popular option for ornamental fencing. What is thought to be iron fencing is often galvanized steel tubing. It is preferred due to its ability to resist rust.
Galvanized steel is used to frame heavy-duty vehicles such as trucks and buses, and galvanized steel parts are found in automobiles and commercial construction vehicles.
Because it is rust-resistant, galvanized steel is also used in household appliances that may be exposed to water and therefore more susceptible to corrosion, such as washing machines and dish washers.
When Not to Use Galvanized Steel
Though galvanized steel may be the best option in many applications, it is not the answer in every job. Galvanized steel is an excellent choice in most situations where water exposure may occur, but it tends to perform poorly when exposed to salt water. The salt renders the zinc coating ineffective and will ultimately result in a rusted product.
Additionally, galvanized steel nails should not be used when constructing cedar fencing. The zinc coating reacts with a naturally occurring enzyme in the cedar, and over time will result in black stains running from the site of the nail down the length of the cedar picket.
What is Stainless Steel?
Stainless steel is made when a concentration of chromium of at least 10 percent is added to molten steel. The steel, in its liquid state, is poured, pressed or formed. When it cools and hardens, stainless steel is formed. The hardened steel is also subjected to acid treatments, called pickling, which remove any impurities on the surface of the steel, and passivation, which forms a noncorrosive layer on the surface of the steel.
Uses for Stainless Steel
Stainless steel is the primary metal used in construction. It is particularly attractive for building applications because of its strength and resistance to rust. Skyscrapers are framed with it and homes are constructed with it. Stainless steel is used to manufacture pipe for building as well as plumbing. It is used for most hardware, hand tools and saw blades.
Stainless steel is an effective material for use in marine environments. It resists rust and holds up well in wet and salty environments.
It is used for the mechanics and exteriors of household appliances, and is the material of choice for most cutlery. Stainless steel can also be found in furniture and jewelry.
When Not to Use Stainless Steel
Stainless steel should not be used when any two pieces have the potential to rub together. Friction may break down the oxide layer of the steel and the pieces may actually weld together. Additionally, stainless steel is a poor choice if there is potential exposure to chlorine. Chlorine eats through the oxide layer of stainless steel, making it susceptible to corrosion. For this reason, stainless steel should never be cleaned with any solution containing chlorine bleach.