How to Save Money When Buying Comparison: Galvanized vs. Stainless Steel Pipe Fittings

Galvanization is a process designed to help steel resist corrosion and provide protection to keep it looking and performing great.

You will get efficient and thoughtful service from JIANZHI.

However, these are all key traits of stainless steel as well.

So which is better for your next project?

In this guide, we’ll compare stainless steel and galvanized steel across a variety of common considerations and use types to help highlight the strengths and weaknesses of these two popular steel variations.

What is Galvanized Steel Anyhow?

Before we can compare them, it’s essential to understand how galvanized steel is made. 

Essentially, galvanized steel is simply zinc-plated steel. 

There are multiple ways to galvanize steel parts and components, but they all provide similar results as long as they are correctly performed.

The most common method of galvanizing steel is hot-dipping. 

In this process, standard steel is dipped in molten zinc, creating a layer of zinc that bonds with the surface of the steel, providing protective benefits and an appealing appearance.

Electro-dipping and thermal diffusion methods are also used when parts are particularly small or complex.

This layer of zinc serves the same purpose as the passive layer of chromium oxide on the surface of stainless steel, helping the metal resist corrosion and repel scuffs, dings, and other minor physical abuses.

This also means that you end up with a layered finished product instead of a fully alloyed product like stainless steel.

So Is Galvanized Steel as Corrosion Resistant as Stainless Steel?

In general, no.

However, this will depend on the specific situations in which you plan to use your galvanized or stainless steel parts.

Galvanized steel offers excellent resistance against water and chlorine but pales in comparison to stainless steel’s corrosion resistance when dealing with marine environments.

The protective layer on galvanized is also not self-healing like the passive layer on stainless steel. 

This means that over extended periods, galvanized parts are generally less durable than stainless ones.

However, even if the zinc layer on a galvanized component is damaged, it will still serve as a sacrificial cell in galvanic corrosion processes, encouraging rust formation on the damaged zinc areas instead of the underlying steel.

In general, stainless will offer better corrosion resistance and offer it for a longer period as well.

Which is Stronger: Galvanized or Stainless Steel?

When compared at similar thicknesses and forms, stainless steel is always stronger than galvanized steel.

An effective way to compare this is by looking at the tensile strength of each material. 

Tensile strength is the resistance of a material to breaking under tension. 

Exact figures will vary by the alloy in use. 

The tensile strength of stainless steel alloys typically starts around 515 megapascals (MPa) and can reach as high as megapascals (MPa) in some cases. 

Structural steel has a tensile strength of 400 megapascals (MPa), while carbon steel has a tensile strength of 841 megapascals (MPa). 

Both are commonly used for creating galvanized steel productions.

Since galvanization does not impact the tensile strength of the underlying metal, you could reasonably expect galvanized steels made from various steel grades to have comparable tensile strength compared to the original steel.

Is Stainless Steel Heavier than Galvanized Steel?

In most cases, stainless steel and galvanized steel will have a very similar weight. 

The specific differences will vary depending on the exact stainless steel alloys in question and the zinc coating thickness on the galvanized steel product.

More alloyed metals or a thicker coating will result in greater weight. This is unavoidable.

How Malleable are Stainless Steel and Galvanized Steel?

Galvanized steel offers the same malleability as the underlying steel used. 

This means that in most cases, it will be more malleable than comparably shaped stainless steel forms. 

If you must use stainless steel and want greater malleability but aren’t sure how to pick the perfect stainless steel grade, consider austenitic grades. 

These contain higher amounts of nickel, making them more formable for larger objects like sinks, basins, and tanks.

How Well Do Stainless Steel and Galvanized Steel Conduct Heat?

Both stainless steel and galvanized steel should conduct heat in a relatively similar manner. 

However, in the case of galvanized steel, you must keep the melting temperature of zinc in mind. 

While molten zinc is non-toxic, heating galvanized steel past zinc’s melting point could create burn or fire hazards as the zinc coating liquefies and separates from the underlying steel.

On a structural level, both types of steel should provide excellent heat tolerances for use in high heat areas.

Can You Weld Stainless Steel and Galvanized Steel?

Both stainless steel and galvanized steel are weldable. However, both feature unique considerations.

Welding stainless steel can degrade the passive layer and create brittleness. 

This can lead to reduced corrosion resistance or compromise the structural integrity of the stainless steel parts in question.

Pickling treatments can help to reduce the impact of welding and heat exposure in most stainless applications.

You must adequately capture or ventilate welding fumes with galvanized steel as zinc oxide fumes can be harmful when inhaled. 

If welding near stainless steel, you must also be sure to keep any molten zinc created away from the stainless components. 

Failure to do so can result in embrittlement of any affected stainless.

For these reasons, it’s recommended to perform welding before galvanizing whenever possible.

Are Stainless Steel or Galvanized Steel Magnetic?

This answer will entirely depend on the family of steel used.

For galvanized steel, if the steel which was covered in zinc was magnetic, the zinc coating should not interfere with the magnetic response. 

If you’re intentionally looking for (or want to avoid) magnetic steel options, austenitic steels are the most magnetic. 

Other alloys will exhibit various levels of magnetism based on their iron content.

Is Stainless Steel or Galvanized Steel Better for Food Service?

Both metals will offer safe, effective use in most foodservice environments.

Galvanized steel is an extremely popular option for building shelving for walk-in coolers. 

It also provides a unique appearance for serving platters and other decorative elements.

However, you must take care to avoid highly acidic foods around galvanized steel as they can degrade the zinc layer surprisingly fast with regular exposure.

Stainless steel is less reactive, so if you’re looking for a more versatile option, it’s your best bet.

Galvanized steel is also not as smooth as many stainless steel finishes and gets coarser over time. 

This means that clean-up requirements will increase over time along with the change in surface texture. 

Related Guide: Stainless Steel Use in the Food Service Industry

Is Galvanized Steel or Stainless Steel More Popular for Medical Use?

In almost all cases, stainless steel will win out over galvanized steel in the medical environment. 

Medical uses, such as equipment, tools, or even implants, require long-lasting performance and easy to clean surfaces.

Whether you’re talking about scalpels or surgical theatre surfaces, you’re likely to see stainless in use nearly everywhere.

Galvanized steel’s coarse surface and the ability for the zinc coating to scratch or chip make it less safe for medical use and potentially more challenging to clean.

Related Guide: Effective Stainless Steel Usage in Medical Environments

Does Stainless Steel Cost More Than Galvanized Steel?

While exact price differences depend on market conditions, stainless steel will almost always cost more than galvanized steel.

Affordability is one of the biggest reasons to choose galvanized steel over stainless steel. 

When long-term use isn’t critical, or the components won’t see frequent use or abuse, galvanized offers a solid alternative to stainless in many ways.

Both metals are recyclable. 

However, galvanized steel is often turned into more standard steel, which must go through the galvanization process again. 

Recycling stainless steel is more straightforward, simply going from solid to molten and back again with monitoring and adjustments to address any impurities or alter the alloy in desired ways.

Contact us to discuss your requirements of Installation method and life maintenance guide for galvanized pipe fittings. Our experienced sales team can help you identify the options that best suit your needs.

Common Uses for Stainless Steel

Stainless steel’s versatility, durability, and easy cleaning and maintenance make it ideal for many uses. 

However, common industries where you might find stainless in action regularly include:

• Aerospace

• Agriculture

• Architectural

• Automotive

• Construction

• Electronics

• Foodservice

• Heating

• Home appliances

• Manufacturing

• Marine

• Medical

• Oil and gas

• Pharmaceutical

• Power generation

• Pulp and paper

• Sports equipment

Common Uses for Galvanized Steel:

Often viewed as an affordable alternative to stainless steel, galvanized steel sees regular use in a variety of industries, including but not limited to:

• Agricultural

• Automotive

• Construction

• Foodservice

• Heating and Air

• Manufacturing

• Power generation

• Telecommunications

In most cases, you’ll see that industries use both metals, taking advantage of the strengths of each while avoiding apparent weaknesses. 

So Which Metal is Best for Your Needs?

Ultimately, as with most metal choices, stainless steel or galvanized steel isn’t automatically best for everything. 

Some differences will make them more or less suited for various uses. 

The outstanding corrosion resistance, easy maintenance, and superior strength of stainless steel make it an ideal choice in a vast range of situations. 

However, if the strength and corrosion resistance aren’t required, you’ll likely pay more for stainless steel components than galvanized ones. 

So when it comes to efficiency, it pays to research your needs thoroughly.

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.

• While both stainless steel and galvanized steel will offer comparable heat tolerances in terms of structural strength, you must take care to avoid melting the zinc coating on galvanized steel parts and components.

• Welding stainless steel is safer and more accessible than welding galvanized steel as zinc oxide fumes can create hazardous conditions, and molten zinc can damage nearby stainless components.

• Galvanized steel is often more malleable than stainless steel, though this will depend on the exact grades of steel used.

• Galvanized steel is almost always lower priced than stainless steel. When cost is the most critical factor, galvanized steel is the way to go. If service life is the biggest concern, stainless will likely outperform galvanized over the longer term.

As one of Canada’s leading suppliers of stainless steel parts, components, and materials, Unified Alloys combines an extensive range of products with more than four decades of experience to ensure your needs are met at every stage of the buying process. Contact one of our expert sales analysts today to discuss options and highlight ways we can help supply your next project!

References:

Galvanized pipe fittings and stainless steel pipe fittings are both widely used in pipelines and industrial fields, but there are obvious differences in material, corrosion resistance, strength and cost. Which material is more suitable depends on the specific application and environmental conditions.

Material composition and corrosion resistance

Galvanized pipe fittings

● Material composition: Galvanized pipe fittings are usually made of cast iron and are treated with hot-dip galvanizing or cold-dip galvanizing (chemical galvanizing) to cover their surface with a layer of zinc.

● Corrosion protection: The zinc layer acts as a sacrificial protective layer to prevent the pipe fittings from rusting; even if the coating is damaged, the zinc will corrode preferentially, thereby protecting the substrate. For galvanized pipe fittings, the thickness of the zinc coating is particularly important. The international standard zinc coating thickness is not less than 70 microns, and the average zinc coating thickness of JIANZHI galvanized pipe fittings is not less than 100 microns. The zinc coating thickness of JIANZHI pipe fittings is 40% higher than the international standard thickness. However, this protective effect is limited in harsh environments (such as marine environments or exposure to highly corrosive chemicals).

● Limitations: The zinc layer is not self-repairing, and once damaged, the durability of the pipe fittings will decrease over time.

Stainless steel pipe fittings

● Material composition: Stainless steel is an alloy containing at least 10%–11% chromium (usually nickel and molybdenum), which forms a self-repairing passive oxide film (chromium trioxide) on the surface, providing excellent corrosion resistance.

● Corrosion resistance: This self-repairing passive film allows stainless steel to exhibit far superior corrosion resistance than galvanized pipe fittings in harsh environments (including salt water environments), because stainless steel pipe fittings also contain chromium, which will react with oxygen to form chromium trioxide with a stable structure, which prevents oxygen and water from penetrating the passivation film, thereby isolating oxygen and water. Suitable for medical and food processing fields with extremely high durability requirements.

● Advantages: Even if the surface is scratched, the passivation film (chromium trioxide) can be re-formed to provide continuous protection.

Strength, Durability and Weldability

Galvanized Fittings

☑ Strength: Galvanized fittings retain the strength of cast iron, but the zinc coating itself contributes less to structural strength.

☑ Durability: Suitable for many general applications; however, service life may be shorter in high-stress or highly corrosive environments.

☑ Welding Considerations: Toxic zinc oxide fumes may be released during welding, and welding may damage the protective coating, requiring post-weld re-galvanizing to restore protection.

Stainless Steel Fittings

☑ Strength: Stainless steel is generally stronger than galvanized fittings of the same thickness, with tensile strengths ranging from 515 to MPa, depending on the alloy.

☑ Durability: Excellent long-term performance and superior corrosion resistance for demanding, critical applications.

☑ Welding Considerations: Special techniques are required to prevent degradation of the heat-affected zone, but when properly welded, stainless steel fittings maintain their excellent corrosion resistance.

Cost considerations

Galvanized pipe fittings

● The material and manufacturing costs are low, and the processing is simple and traditional, but it is labor-intensive, and the labor costs account for the majority.

● Applicable to places with limited budgets and low corrosive operating environments.

Stainless steel pipe fittings

● Due to the high price of raw materials and complex manufacturing processes, their cost is usually about five times higher than that of galvanized pipe fittings.

● In harsh environments with long-term use and low maintenance costs, high initial investment can be exchanged for longer service life and lower maintenance costs.

Application scenarios

Suitable for galvanized pipe fittings:

● Applicable to indoor pipes, drainage systems, and budget-constrained and moderately corrosive environments.

● Commonly used in construction, especially in places where exposure to highly corrosive substances is not frequent.

● Galvanized pipe fittings are more common in water and fire protection systems and gas systems.

Suitable for stainless steel pipe fittings:

● Stainless steel is the first choice when higher corrosion resistance is required (such as marine, chemical, medical or high humidity environments).

● It is also often used in fields with high requirements for appearance, such as food service and architectural decoration, because of its smooth and beautiful appearance.

● Pipeline installation in coastal areas, chemical plants and medical equipment production, these high-standard and high-demand application scenarios will use more stainless steel pipe fittings.

In summary, the choice of galvanized pipe fittings or stainless steel pipe fittings depends mainly on the project requirements:

☑ Galvanized pipe fittings are economical and practical, suitable for most conventional applications, but may not be durable enough in extreme environments.

☑ Stainless steel pipe fittings provide higher strength and corrosion resistance, and are the best choice for harsh environments and applications with high durability requirements.

☑ The final decision requires a trade-off between initial cost, expected service life and maintenance requirements. Stainless steel is usually a longer-term investment in places exposed to harsh environments or with strict hygiene requirements.