Galvanized Steel vs Stainless Steel: Which Is the Better Choice? | Crossroads Galvanizing (2024)

FAQs

Galvanized Steel vs Stainless Steel: Which Is the Better Choice? | Crossroads Galvanizing? ›

If you're not sure where to start, consider these points: Stainless steel is almost always more robust than galvanized steel. So if structural elements are involved, stainless will likely be a better bet. Stainless steel provides stronger corrosion resistance than galvanized steel -- especially in marine environments.

In general, galvanized steel is more ductile, and easier to work than stainless steel. Stainless steel is stronger and more corrosion-resistant than galvanized steel.

Galvanized steel is steel that features a zinc coating, which helps to create a barrier between the steel and the air and moisture, protecting it from rust. Stainless steel is steel that is mixed with at least 10% chromium to create an alloy that is corrosion-resistant, as well as bacteria-resistant.

The iron elements in steel are incredibly prone to rusting, but the addition of zinc acts as a protective buffer between the steel and any moisture or oxygen. Galvanized steel is very protective, including sharp corners and recesses that couldn't be protected with other coatings, making it resistant to damage.

The risk of galvanising corroding when used with stainless depends on a number of factors. For instance, hot dipped galvanised has better corrosion resistance than electro polished galvanised. However, in marine, salty or moist areas, even hot dipped galvanised used with stainless steel will cause corrosion.

Stainless steel lasts much longer than galvanized steel, so when the longevity of the building project is of importance, using stainless steel is recommended. Stainless steel is much stronger than plain steel hotdip galvanized.

The manufacturing process makes stainless steel a more expensive choice than galvanised steel. However, stainless steel is generally stronger than its galvanised counterpart. Stainless steel can also be finished in many different ways, providing a high degree of customisability in terms of its final appearance.

Stainless steel and the zinc in galvanized steel are very dissimilar and will react to each other. When an electrolyte (like water or saltwater) is present, the stainless steel becomes a negatively-charged cathode, and the zinc in the galvanized steel becomes a positively-charged anode.

While galvanized steel is more supple and easier to work, stainless steel resists corrosion better and is stronger. The zinc that coats galvanized steel protects it from rust by keeping the steel from coming into contact with oxygen, which causes corrosion.

Zinc alloys are more corrosion-resistant than stainless steel, but stainless steel is more heat-resistant. Zinc alloys are weaker than stainless steel but are also less expensive. Stainless steel is available in various grades depending on its intended use, while zinc alloys only come in one grade.

What are the disadvantages of galvanized steel? ›

It's resistance to corrosion makes it ideal to transport chemicals, liquids and food products. The low maintenance of stainless steel also makes it an easy and cost-effective metal to clean and sustain. Stainless steel is preferred in clean and sterile environments as it is simple to clean and does not easily corrode.

In short, while it's impossible to always avoid contact between stainless steel and galvanised steel, it is recommended to avoid it where possible, especially in wet or salty conditions.

Galvanization is a zinc coating applied over the top of steel. It prevents rust and corrosion far longer than paint will, often for 50 years or more, but eventually that brown rot will set in.

It offers more corrosion resistance than galvanized steel, making it a great choice for marine and aerospace applications. One major drawback is the cost: stainless steel can be about five times more expensive than galvanized steel.

Galvanized steel takes a long time to rust, but it will eventually rust. This type is carbon steel that has been galvanized or coated with a thin layer of zinc. The zinc acts as a barrier preventing oxygen and water from reaching the steel, providing advanced corrosion protection.

So, Does Galvanized Steel Rust? It may sound too good to be true, but because of its chemical properties, it is nearly impossible for galvanized steel to rust. It can, and may if it remains exposed to intense elements in difficult environments for decades.

So, how do you achieve this? One simple way is to clear coat the surface. Using a clear coat extends the lifespan of the steel and makes it look better. Clear coating your steel also helps to prevent fading, oxidizing and damage from UV rays.

Cast iron and galvanized steel are resistant to saltwater but over time due to exposure will succumb to corrosion. Plastic is the most resistant to salt water corrosion. However there are preventative solutions to make sure salt in water does not corrode pipes.

Although virtually any type of paint will bond to a properly prepared stainless steel surface, a two part epoxy paint is the preferred coating – here is a great guide on how to paint stainless steel.

What metals should not be used together? ›

Stainless with stainless, aluminum with aluminum, brass with brass. Mixing metals can affect the strength of the application, the lifespan of the fasteners, the corrosion of the materials, etc.

A zinc plated nut would not fit properly on a galvanized bolt.

A less common environment for galvanized steel is submerged in or exposed to water. Moisture is highly corrosive to most metals including steel and zinc.

Under atmospheric conditions of moderate to mild humidity, contact between a galvanized surface and a stainless steel surface is unlikely to cause substantial corrosion. However, if the surfaces are in the presence of salt water or salt water air, it would be best to electrically isolate the two metals.

A product that is hot dip galvanised will have a thicker coating, meaning it will last far longer. Hot dip galvanised coatings give superior protection against corrosion. The images below show that zinc plated gate hardware will rust over time.

Even with these impressive features, stainless steel can and does rust after all, it's 'stainless' not 'stainfree'. Some types of stainless steel are more prone to corrosion than others, depending on the chromium content. The higher the chromium content, the less likely the metal will rust.

Though some Zinc alloys can be very strong, overall stainless steel is stronger. However, zinc is a heavy element, and when alloyed with other metals it provides better corrosion resistance, stability, dimensional strength and impact strength.

Galvanizing is a favored method of protective coating due to its low cost, ease of application, and long maintenance-free service life. Generally applied at 830 to 870 degrees, the zinc will bond with the steel. It is the most common outdoor protective coating in use.

Brass and copper are reliable metals to use for the great outdoors. Copper is resistant to corrosion, malleable, and strong. Brass is the result of the combination of copper and zinc, and its color will vary based on the amount of zinc in the alloy.

The zinc-iron alloys can be harder than the base steel. A galvanized coating can also help prevent damage during construction, where its toughness can protect components during transport, erection and the other mechanical activities. Overall a galvanized coating has a high corrosion prevention value.

What are the cons of hot dip galvanizing? ›

Long term health concerns

There is a small lead content on the galvanized coating. When welding, this lead will vaporise and form lead oxide fumes. These gases can cause long-term health problems such as lung and brain cancer and even complications in the nervous system.

Galvanized steel is much stronger than aluminum and can withstand greater pressure levels without buckling or deforming. It's also highly resistant to corrosion due to its zinc coating, which helps protect it from rusting or corroding when exposed to moisture or pollutants.

They are highly durable and resistant to damage, making them the perfect choice if you want to make a lasting investment in your kitchen. Stainless steel is resistant to heat, water damage and rust, an important factor when you're choosing a kitchen appliance.

The most important characteristic is that stainless steel never oxidizes or rusts as other iron and steel products do. Corrosion resistance, aesthetic appeal, low-maintenance, and strength make stainless steel a popular choice for a variety of applications.

Stainless steel is popularly used for cookware, kitchen utensils and cutlery. This is because it's hardwearing, corrosion resistant, and it doesn't affect the flavour of the food when used for food storage or production. Due to the resistance level, foods with high acidity won't cause damage.

Double dipping is a process used by galvanisers when a steel fabrication is too large or otherwise difficult to fit in their bath at just 1 angle. In simple terms, the fabrication is dipped more than once, at different angles to ensure that all of its surfaces receive an adequate coating of zinc.

Previously hot-dip galvanized steel is easier to re-galvanize, as long as some thickness of the original coating remains. The old coating can be stripped in the pretreatment process (acid pickling), exposing what is virtually new steel for galvanizing.

Fluoropolymer Coatings

Fluoropolymers, such as Whitford's Xylan series, are another excellent choice to combat galvanic corrosion. These coatings are considered a barrier coating that stops harmful substances from reaching the substrate.

What is the lifespan of stainless steel? ›

Stainless steel refers to any kind of steel containing a chromium content greater than 10.5% and with a lifespan of over fifty years. Stainless steel is easy to sterilise, 100% recyclable, and used in many applications. In contrast to regular steel, stainless steel is prone to rust and corrosion due to water exposure.

Galvanized metal containers are not considered safe for cooking or storage of food. The galvanizing process creates a coating to the metal that prohibits rust. This coating contains zinc, which can be toxic when consumed. Cooking utensils and storage containers are commonly not made of galvanized steel.

Galvalume^® is more corrosion-resistant than galvanized steel, but because aluminum provides barrier protection instead of galvanic protection, scratches and cut edges are less protected. Galvalume is offered in both bare and pre-coated versions. Most Galvalume^®–like galvanized steel– is coated.

While the zinc coating does mostly prevent the steel from rusting, it is only about a millimetre thick, meaning if it is scratched or cut too deep, it will rust due to exposure to oxygen. Due to its easy process to make, low cost and durability, galvanised steel is a popular choice of metal.

Stainless steel has superior corrosion resistance compared to other materials. Therefore, stainless steel is perfectly suited to variety of environments. However, it is worth noting that despite its resistance to corrosion, there are certain chemical environments that can cause issues for stainless steel equipment.

Because of their durability and longevity, stainless steels are typically in use for many years before they become available for recycling. The average lifespan is estimated to be around 20 years, but there are examples of stainless steels in use for a century and beyond.

In short, while it's impossible to always avoid contact between stainless steel and galvanised steel, it is recommended to avoid it where possible, especially in wet or salty conditions.

Even with these impressive features, stainless steel can and does rust after all, it's 'stainless' not 'stainfree'. Some types of stainless steel are more prone to corrosion than others, depending on the chromium content. The higher the chromium content, the less likely the metal will rust.

Stainless steel is durable, as it is resistant to rust and corrosion and designed to withstand the outdoor elements.

The most important step in preventing corrosion on galvanized steel is keeping it out of environments where it is exposed to substances with a pH below 6 or above 12. One side of this requirement is that it is important to keep galvanized steel out of acid rain.