Galvanized Steel: What is it Used For

What Galvanized Steel is Used For

Last month we discussed how galvanized steel is made. Now, I think it is time to talk about what it is used for.

Galvanized steel Ductwork

Christina Bajarano “Ductwork”

HVAC

Galvanized steel is most commonly seen in HVAC equipment and ductwork. Although typically hidden behind ceilings and walls, many buildings are now embracing open ceilings and architecturally exposed ductwork. You may come across this in coffee shops, small restaurants, business buildings, and even in some contemporary homes.

The color of the exposed ductwork can vary as galvanized is easily paintable. Common colors include brown, black or white. I’ve even seen it in purple. However, it is also common to see the raw galvanized spangle.

Construction

Galvanized steel is also heavily used in construction. Due to its rust resistance and durability it can be used for roofing, siding, support beams, and railings. If you live in a region that experiences larger amounts of rain or snow throughout the year, it is likely your rain gutters are constructed from galvanized steel. This is because the metal is stronger and more durable than the vinyl used by other dry regions.

Skip swinging on galvanized steel playground

EvelynGiggles “Swinging” (altered)

Playgrounds

Do you remember the days when you used to go to the park and swing on the swing set for hours? It is quite possible that your old favorite swing set, or even your new swing set-I don’t judge, is constructed from galvanized steel. This also includes jungle gyms, slides, and bicycle racks.

There are countless uses for galvanized steel. A couple of my personal favorites are galvanized wash tubs and whiskey barrels bound together with galvanized strips. It may sound odd that of all things those are my favorite galvanized products, but they are aesthetically pleasing in gardens. They also make handy drink buckets.

Other uses include garbage cans, lighting fixtures, buckets, automobile parts, household appliances, and home décor (I have a large galvanized “K” hanging on my wall).

Galvanized Steel: How it is Made

Galvanized steel coils, ofr metalsMany people know what galvanized steel is. It is used for a wide variety of applications ranging from HVAC ductwork to gardening pails; household decorations to garbage cans. The spangle finish on the surface makes it visually appealing, but also makes it more durable and corrosion resistant.

So, how is galvanized steel made? Where does that spangle come from? Well, let’s find out.

Hot-Dip Galvanization

Galvanized steel is a carbon steel that has been coated with zinc. The most common method of zinc coating is the hot-dip process.

The hot-dip process consists of submerging the carbon steel into a molten zinc bath (approximately 680 degrees Fahrenheit). When the material is removed from the zinc bath and cooled a reaction to the oxygen in the air occurs. The reaction causes the zinc to become part of the steel (an iron-zinc alloy bond). The new surface finish appears to have a crystalline finish or spangled finish.

While this is the most common form of galvanization, it is often used for steel products that have previously been fabricated as the thickness of the final product is not easily controlled. Another method of the galvanization process is continuous galvanizing.

Continuous Galvanizing

Continuous galvanizing applies the zinc coating to the surface of a continuous ribbon of steel (coil) as it passes through a zinc bath. The coil travels at speeds of approximately 600 feet per minute.

As the coil leaves the zinc bath it carries with it an extra layer of molten zinc. The extra zinc is removed with high pressure air (air knives) to create the desired thickness. The material is then allowed to cool and the spangled finish is formed.

Skip with Galvanized Steel FinishContinuous galvanizing allows for more precise control of the thickness and is typically used for steel products that have not yet been fabricated. As the coating thickness increases, the risk of losing some coating during fabrication or forming also increases.

Overall Surface Finish

Galvanized coil and sheet are produced for applications in which corrosion resistance is important. The zinc coating lengthens the life of the end product, making it desirable for manufacturers. The appealing surface finish also makes it desirable for the consumer.

Stainless Steel: What it is Used For

When many people think of steel, they think of stainless-at least that is what I thought of before I came to work for a steel company. The reason behind this is that it is used in numerous applications.

What Stainless Steel is Used For

In a previous post we discussed how stainless steel is made. We discovered how it was mined, melted, hot rolled, cold rolled and, finally, finished. Today, we will find out what that finished stainless steel material is used for.

stainless steel foodservice equipmentKitchen Equipment

One of the most common places you will find stainless steel is in the kitchen. Whether that kitchen is in your home or the restaurant you are eating at it likely has stainless in it somewhere. For time’s sake, we will focus on commercial kitchens.

Kitchens in restaurants are typically 85% (rough estimate based on personal waitressing experience) stainless steel. From the dish line and prep tables, to the walk in coolers and the fryer everywhere you look in a commercial kitchen is shiny metal. This is due to the corrosion resistance to high temperatures and other elements as well as the sanitary properties the metal holds.

The next time you go out to eat, take a peak in the kitchen. You will likely see about 85% of the kitchen is shiny stainless steel.

OK so, you don’t go out to eat-no offense, but that is just weird. Well, there are other applications of stainless steel that might interest you.

distillery equipment

Photo Credit: Brent Rostad

Brewery & Distillery Equipment

Maybe you like to have a cold beer or refreshing Jack and Coke after a long day at work? I mean, am I right? In the event that I am, you may like to know that brewery and distillery equipment is largely made of stainless steel. Similar to foodservice equipment, stainless is use in beverage equipment due to the sanitation aspect, but also because of the strength of the material. Stainless 304 is largely used in beverage equipment.

The Bean, stainless steel architecture

Photo Credit: Vincent Desjardins

Architectural Components

You don’t drink. That is just fine! Did you know stainless is also used for architectural trim? Stairways, windows, doors and building accent pieces can all have stainless trim. I am a fan of beautiful and intriguing architecture, especially when it comes to unique ways to use stainless steel. Some of my personal favorites include “The Bean” in Chicago’s Millennium Park (by Anish Kapoor) and the Walt Disney Concert Hall in Los Angeles (by Frank Gehry).

These are just some of the applications stainless steel can be used for. It is also found in automotive trim, railway and subway cars, and many other applications.