Nickel-containing stainless steel reinforcement is increasingly used to ensure infrastructure such as bridges, flyovers (overpasses) and tunnels can pass the test of time, even in the harshest of environments.

Stainless steels have been used in construction ever since they were first invented over a hundred years ago. Stainless steel products are attractive and corrosion resistant, need little maintenance and offer good strength, toughness and fatigue properties. Stainless steels are straightforward to fabricate and are fully recyclable at end-of-life. They are the material of choice for applications situated in challenging environments, including industrial processing facilities, buildings and structures in coastal areas or where there is exposure to de-icing salts. The high ductility of stainless steel is a useful property where resistance to seismic loading is required.

Typical applications for austenitic and duplex grades include:

  • Beams, columns, platforms and supports in water treatment processing plants, pulp and paper manufacture, nuclear, biomass, chemical, pharmaceutical as well as the food and beverage industries

  • Primary beams and columns, pins, barriers, railings, cable sheathing and expansion joints in bridges

  • Seawalls, piers and other coastal structures

  • Reinforcing bar in concrete structures

  • Curtain walling, roofing, canopies, tunnel lining

  • Support systems for curtain walling, masonry, tunnel lining, etc.

  • Security barriers, hand railings, street furniture

  • Fasteners and anchoring systems in wood, stone, masonry or rock

  • Structural members and fasteners in swimming pool buildings (special precautions should be taken in structural components in swimming pool atmospheres due to the risk of stress corrosion cracking)

  • Explosion and impact resistant structures such as security walls, gates or bollards

  • Fire and explosion-resistant walls, cable ladders and walkways on offshore platforms

Structural applications


Stainless steel is a highly versatile material, possessing a unique selection of properties that can be exploited in structural (load-bearing) applications.
Sheet, plate, bar and tubular products are all widely available in austenitic and duplex grades of stainless steel. A range of hot-rolled or welded structural sections (I-sections, angles, channels, tees, hollow sections) are stocked in standard austenitic material. Duplex stainless steel usually requires special orders. Other structural sections can be produced by cold forming, extrusion or laser fusing. A wide range of stainless steel bolts, screws and other types of fasteners are available.
For information on availability, contact your local stainless steel development association.

©Tim Fisher
©Tim Fisher


Structural applications of stainless steel in infrastructure include load-bearing components in pedestrian, road and railway bridges (girders, arches, tension rods etc) and tunnels (support framing for lining, maintenance walkways, lighting and signage supports). Stainless steel is also widely used for street furniture (barriers, handrails) and for the entrance structures to underground stations.


In commercial buildings and structural exteriors, stainless steel structural components are a popular choice for supporting glass curtain walls as well as for canopy supports, balconies and other applications requiring corrosion resistance and strength in order to reduce maintenance requirements.
Stainless steel is an ideal material for fastening wood, stone and masonry, anchoring systems and support angles. These connections can often be inaccessible or difficult to replace. Additionally, wood and masonry can be inherently corrosive to other metals and are likely to absorb moisture and corrosive chemicals over time.
In swimming pools, stainless steel is used both for architectural and structural applications such as pool liners, handrails, ladders, structural components, fasteners, furniture, diving structures, decorative items as well as water treatment and ventilation systems. However, special precautions need to be taken for stainless steel structural components containing high residual stresses in swimming pool environments due to the risk of stress corrosion cracking.

Industrial structures

Stainless steel is used for explosion and impact-resistant structures such as blast and security walls, gates, security barriers and bollards. This is because it can absorb considerable impact without fracturing, due to its excellent ductility and strain-hardening characteristics. This high ductility is a useful property where resistance to seismic loading is required.

Stainless steel is increasingly used in industrial structures for the water treatment, pulp and paper, nuclear, biomass, chemical, pharmaceutical, and food and beverage industries. Industrial structural applications include platforms, barriers/gates and equipment supports.

Grade selection

Stainless steels used in structures

The vast majority of structural stainless steel applications use austenitic or duplex stainless steels.
Austenitic stainless steels provide an excellent combination of corrosion resistance, forming and fabrication properties with design strength of approximately 220 MPa (32 ksi). They contain about 10 percent nickel. The basic chromium-nickel austenitic grades, S30400/S30403, are suitable for rural, urban and light industrial sites. The chromium-nickel-molybdenum austenitic grades, S31600/31603 are more highly-alloyed grades and will work well in marine and industrial sites.
Duplex stainless steel, such as grade S32205 has a high strength of around 450 MPa (65 ksi), good wear resistance and excellent resistance to stress corrosion cracking. It is called ‘duplex’ because it has a two-phase microstructure consisting of grains of ferritic and austenitic stainless steel and contains about 5 percent nickel.
In addition, the newer, lean duplex grades offer high strength combined with a leanly-alloyed chemical composition, making them less expensive. Examples of lean duplex grades are S32101 and S32304. Nickel content is about 2-4 percent.
Ferritic stainless steels are used occasionally for structural applications, generally in thicknesses of 3 mm and below. They usually contain little or no nickel additions.

Material and product specifications

European and American standards giving chemical compositions and mechanical properties for flat and long products stainless steel are:

Stainless steel bolts specifications include:

  • EN ISO 3506 Mechanical properties of corrosion-resistant stainless steel fasteners
  • ASTM F593 Standard Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs
  • ASTM A1082/1082M Standard Specification for High Strength Precipitation Hardening and Duplex Stainless Steel Bolting for Special Purpose Applications

An extensive list of international specifications is available here:
International Specifications, Guidelines & Industry Associations for Architecture, Building and Construction

Choosing the right grade

It is important that the stainless steel chosen is appropriate for the intended service environment, as the cost generally increases with the corrosion resistance.
A procedure for selecting the correct grade of stainless steel for structural applications in different environments can be found in Eurocode 3: Part 1.4 (EN 1993-1-4), the European design standard for structural stainless steel. The severity of the environment is determined based on an assessment of the risk of exposure to chlorides (from salt water or de-icing salts) and to sulphur dioxide. The cleaning regime, including whether the structure is exposed to washing by rain, is also taken into account. The selection procedure is fully explained, with examples, in the SCI Design Manual for Structural Stainless Steel (4th Ed) (published in 2017).
Other important considerations are grade/product availability, surface finish requirements and joining methods.
A grade selection tool for architectural stainless steel is also provided by IMOA:
IMOA: Site and design evaluation system

Properties of stainless steels used in structural applications

Stress-strain behaviour

The stress-strain behaviour of stainless steel differs from that of carbon steels. Carbon steel typically exhibits linear elastic behaviour up to the yield stress and a plateau before strain hardening is encountered, whereas stainless steel has a more rounded response, with no well-defined yield stress. The yielding and work-hardening characteristics of stainless steel means that conventional carbon steel design rules do not apply. The austenitic grades have a ‘yield’ strength of about 200-240 MPa (29-35 ksi) and the duplex grades 400-530 MPa (58-77 ksi).
The modulus of elasticity of stainless steel is very similar to that of carbon steel; a value of about 200x103 N/mm2 is generally used for the types of stainless steel used in structural applications.
Stainless steels can absorb considerable impact without fracturing, due to their excellent ductility (particularly the austenitic grades) and their strain-hardening characteristics.
SCI Design Manual for Structural Stainless Steel

Properties at high temperatures

The different composition of stainless steel means different thermal properties compared to carbon steel. The coefficient of thermal expansion of austenitic stainless steels is about 30 percent higher than that of carbon steel, whereas the value for duplex stainless steels is only about 10 percent higher. The thermal conductivity of austenitic and duplex stainless steels is about 30 percent of that of carbon steels.

Austenitic stainless steel exhibits better strength retention than carbon steels at temperatures above about 550ºC and better stiffness retention at all temperatures. As a result, stainless steel columns can retain their load-bearing capacity for longer than equivalent carbon steel members.
SCI Design Manual for Structural Stainless Steel.

Properties at low temperatures

Austenitic stainless steels are extensively used for service in temperatures as low as that of liquid helium temperature (-269°C) because they do not demonstrate a transition from ductile to brittle fracture, even at very these low temperatures.
Materials for Cryogenic Service - Engineering Properties of Austenitic Stainless Steel


The fatigue resistance of austenitic and duplex stainless steel is considered to be at least on a par with that of carbon steel; this is why guidance on estimating the fatigue strength of structures is applicable for carbon steel.
SCI Design Manual for Structural Stainless Steel


Although the initial cost of stainless steel costs more than carbon steel, savings from corrosion-resistant coatings, reduced inspection frequency, maintenance, downtime and replacement costs can far outweigh the higher initial material costs. The benefits of a long service life are particularly valuable in bridge structures, which are conventionally designed for lives of 70-100 years.
Stainless steel is 100 percent recyclable and can be indefinitely recycled into new high quality stainless steel.
Sustainable stainless web site

Design, fabrication and installation

Structural design

The yielding and work-hardening characteristics of stainless steel mean that conventional carbon steel design rules, based on observing the limit of elastic deformation, do not all apply. There need to be different design rules for beams and columns susceptible to local or global buckling. Heavily-loaded beams will deflect more than the equivalent beams in carbon steel.
The following design standards are available:


Fabrication and installation

Many fabrication and joining processes are similar to those used in carbon steel, but the different characteristics of stainless steel require particular attention in a number of areas. For example, precautions should be taken to maintain the steel’s corrosion resistance during storing, handing and forming, etc.
Guidance is given in the SCI Design Manual for Structural Stainless Steel and AISC Design Guide 27: Structural stainless steel on relevant issues concerning the fabrication of structural components. Stainless steel is included in the European specification governing the fabrication and installation of structural steel, EN 1090. Execution of structural stainless steel and Erection and installation of stainless steel components explains the rules relating to stainless steel in this standard.

Other useful reference sources include:

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