Stainless Steel Fabrication: Material Properties, Applications, and Finishes
October 01, 2025
Stainless steel is everywhere, from the countertops in restaurant kitchens to the handrails in public buildings to the cleanroom equipment in pharmaceutical labs.
At Macy Industries, we work with stainless steel every day, designing, fabricating, and installing custom products for industries where performance and appearance matter.
What Makes Stainless Steel “Stainless”
OK, quick chemistry lesson. Stainless steel is an iron-based alloy. (You get an alloy by combining two or more elements to form a new material.) To get stainless steel, you combine iron with at least 10.5% chromium.
The chromium reacts with oxygen to form a thin, invisible layer of chromium oxide on the metal’s surface. This “passive layer” acts as a barrier, protecting the steel underneath from moisture, chemicals, and other corrosive elements. As long as oxygen remains present, the passive layer can repair itself naturally if it’s scratched or damaged.
Certain grades of stainless steel offer even more corrosion resistance because the surface has gone through a chemical cleaning process called passivation. Passivation removes contaminants that could interfere with the chromium oxide layer, helping it do its job even more effectively.
While chromium and iron are the key ingredients in stainless steel, other elements—like nickel, for example—can be added to enhance other properties, such as ease of shaping and welding.
Key Material Properties That Make Stainless Steel So Popular
When a project calls for a material that can handle harsh conditions without losing performance or appearance, stainless steel is often the answer. Here’s why:
Rust and corrosion resistance
Stainless steel stands up to moisture, chemicals, and temperature swings better than most metals, making it ideal for both indoor and outdoor use.
Strength and durability
Stainless steel resists dents, impact, and wear, even in high-traffic or heavy-use environments.
Hygienic surface
Non-porous and easy to clean, stainless steel is a top choice in industries where sanitation matters, such as food service, healthcare, and pharmaceuticals.
Temperature tolerance
Stainless steel performs reliably in hot or cold conditions. Certain grades can withstand extreme temperatures.
Aesthetic appeal
Stainless steel’s clean, modern look works with a wide range of architectural and decorative styles, from sleek and contemporary to classic and ornamental.
These properties make stainless steel one of the most versatile materials in metal fabrication and a staple in many of Macy’s custom projects.
Common Stainless Steel Applications
Stainless steel is one of the most widely used materials in metal fabrication, thanks to its impressive properties.
Example use cases:
Many wastewater treatment facilities require the use of stainless steel materials.
Stainless steel is often used in HVAC applications that tend to have interior condensate or operate in areas susceptible to outdoor elements, such as rain and snow.
Stainless steel with a #4 polish (more on this below) can be used in many decorative applications, such as handrails, signage, countertops, and sculptures.
Example industries:
Food service: Counters, commercial kitchen hoods, sinks, and shelving made from stainless steel are easy to clean, resist bacteria growth, and meet health code requirements.
Pharmaceutical and laboratory: Used in cleanrooms, lab benches, and storage cabinets where sterility and corrosion resistance are critical.
Architectural and structural: From handrails to decorative panels to exterior cladding, stainless steel delivers both strength and style.
Industrial and manufacturing: Ideal for tanks, hoppers, ducting, and equipment enclosures that must withstand heavy use, harsh chemicals, or extreme temperatures.
Bottom line: Stainless steel’s durability, corrosion resistance, and clean appearance make it a go-to material across countless applications and industries.
Finishes and Grades of Stainless Steel That We Work With
The finishes we use include 2B and #4 polish, and the one we go with very much depends on the client’s specific needs and the desired look.
Here’s an overview of the different grades of stainless steel:
304-2B Stainless Steel
This is the most common grade. It offers excellent corrosion resistance and strength. This grade is typically used in industrial applications where the goal is function over aesthetics. For example, think of an industrial tank that houses chemicals.
304 with #4 Polish
This stainless steel grade is most commonly supplied as polished sheets with a protective coating.
316 Stainless Steel
This second most common grade (after 304) provides extra protection against corrosion, especially in environments exposed to chlorides or harsh chemicals. It is commonly used in marine, pharmaceutical, medical/surgical, and chemical processing applications.
Here’s an overview of the finishes:
2B is like a mill finish. Think an untreated surface straight from the mill, often used for industrial applications where appearance is secondary to performance.
#4 polish gives that smooth, shiny, reflective finish for a high-end, modern appearance. The stainless steel appliances you have in your kitchen have a #4 finish. Typically, commercial applications and residential applications use this shiny #4 polish.
Preventing Cross-Contamination
When stainless steel comes into contact with carbon steel, tiny iron particles can transfer to the surface. Over time, those particles can cause rust—undermining the very reason stainless steel was chosen in the first place.
At Macy Industries, we take special care to protect stainless steel throughout the fabrication process. From the way we handle and position materials to maintaining clean work surfaces, we’re mindful of anything that could compromise the integrity of the metal.
Project Highlight: Large-Scale Stainless Steel Exhaust System
One of Macy’s recent large-scale stainless steel projects involved fabricating about 300 feet of laser-welded, rolled stainless steel pipe (type 316) and fittings. The system connected five machines to an industrial scrubber, routed through a large stainless plenum box, exited through the roof curb, and tied into three industrial stainless fans off a single trunk line header system. Each fan was equipped with its own 10-foot, double-walled exhaust stack.
The project began with a 16-inch-diameter pipe, starting as flat sheets. These sheets were sheared and hand-rolled to the necessary diameter, welded at the seam, and finished with fully welded stainless angle iron flanged rings. Over the 300-foot run, we reduced the pipe’s diameter multiple times—from 16 inches to 12, then to 10, 8, 6, and finally 5 inches at the machine connection points.
All piping was hung using stainless threaded rod systems and cantilevered stainless angle iron brackets, ensuring strength, stability, and corrosion resistance throughout the entire installation.
Read more customer stories involving stainless steel fabrication:
At Macy Industries, we’ve specialized in stainless steel fabrication since 1975. Whether you need a small-scale fabrication or an extensive, complex system, we can help. Get in touch to discuss your next project.
