What is the best stainless steel grade for balustrades?

Dec 21, 2021    |    Balustrades

Stainless steel is a great choice for outdoor balustrades and railings of all kinds. Architectural steel has superior strength that guarantees reliable performance and stainless steel is also a material that lends itself to a variety of aesthetic approaches.

The main benefits, however, is its durability and corrosion resistance, making it an extremely cost-effective option in the medium and longer-term.

Stainless steel has quickly become the “go-to” material for architectural projects around the world. It is a material used in nearly every industry and many of the world’s most famous landmarks feature stainless steel within the design.

It is, however, just as practical for smaller projects around the home and office, as well as city architecture and we are finding more and more customers are turning to stainless steel as their preferred option for outdoor and indoor balustrades.

What is stainless steel?

Stainless Steel Manufacturing

Stainless steel is essentially a low carbon steel to which chromium has been added. It is this addition of chromium, in amounts greater than 10.5% by weight, that gives the steel its unique ‘stainless’, corrosion-resisting properties.

The chromium content of the steel allows the formation of a tough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanically or chemically this film is self-healing, provided that oxygen, even in very small amounts, is present.

The corrosion resistance, as well as other useful properties of the steel, are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel, and nitrogen.

These properties make stainless steel the ideal material for balustrades as well as many other applications. It is strong, lightweight and cost-effective and it is a material we use for many of our balustrade projects.

The best grade of stainless steel for balustrades

Whilst stainless steel has become the most popular material, especially for outdoor balustrade projects, it is important to select the best grade of stainless steel for the job at hand. There are four common grades of stainless steel used in architecture, however, typically only two of these are used in balustrade projects: Grade 304 and Grade 316.

The stainless steel you choose for your balustrade needs to be able to cope with the demands of the planned location, as well as fall within your budget.

Here’s a closer look at the two grades of stainless steel we typically use in balustrade projects.

Grade 304 Stainless Steel

Stainless Steel Architecture Interior

Corrosion resistance is a key requisite for outdoor balustrades and 304-grade stainless steel has rust-resistant properties as well as being strong, with good aesthetics. 304 grade stainless steel typically contains around 18% chromium and 9% nickel and is considered to be general-purpose stainless steel that is easy to work with, can be welded and polishes to a high shine.

Whilst we do use this in a number of exterior balustrade projects, it is also well suited to interior projects as well.

The one area where 304-grade stainless steel is not as effective is around coastal environments. It is not as resistant to chlorides and in high-salinity environments, it is not always the best option.

Grade 316 Stainless Steel

A little more expensive than 304-grade stainless steel, 316 grade offers all of the positive properties of 304 grade but with much-enhanced corrosion resistance. Often referred to as “marine-grade” stainless steel, 316 grade contains 18% chromium, 10% nickel and crucially, 2% molybdenum.

The harsh, salt-laden environments found in and around coastal areas, and chlorine-saturated areas in close proximity to swimming pools, will always present corrosive challenges for architectural steel. Whilst 316 grade may tarnish in the harshest locations over time, it is definitely the “go-to” grade of stainless steel for balustrade projects around swimming pools and in areas close to the coast. If budget allows, especially here in New Zealand, we always recommend 316 grade as it offers the greatest degree of corrosion resistance.


If you are thinking about a balustrade installation this summer, talk to the team at SRS Group and we can advise on the best materials for your project.

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