Structural members

By Nancy Baddoo, Ceng, and Mark Holland, PE

Article published in the January 2022 edition of the Modern Steel Construction magazine from the American Institute of Steel Construction.

The article on the new AISC specification for structural stainless steel can be downloaded here
A full copy of the magazine can be obtained here

AISC's updated Design Guide on structural stainless steel provides engineers and others with examples, tips, and advice on creating projects that shine.

Francisco Meza and Nancy Baddoo from the Steel Construction Institute describes the possibilities of the Specification, Code and Design Guide for Structural Stainless Steels.

by Michael Mulhern, PE and Eric Bolin

AISC's new Code of Standard Practice for Structural Stainless Steel Buildings smooths a path for the proper designation and design of structural stainless steel.

In the December 2022 edition of Structure Magazine, Benjamin Baer gave an overview of the new AISC design specification for structural stainless steel, ANSI/AISC 370, and introduced the provisions for designing members. This article focuses on the design of bolted connections in structural stainless steel.

AISC 370 is a new design specification for hot-rolled, extruded, and welded stainless steel sections. It is adapted from AISC 360 and modified to reflect the difference in behavior between carbon steel and stainless steel. A few things from AISC 360 are not currently covered in AISC 370. However, it is not appropriate to use AISC 360 as a substitute for conditions not included in AISC 370. Work on AISC 370 is ongoing, and the next edition in 2027 should cover more situations.

Author: Benjamin R. Baer

Design Guide 27, 2nd Ed., Structural Stainless Steel, provides guidance for the design of structural stainless steel.  It is written for engineers experienced in the design of carbon steel structural components but not necessarily in the design of stainless steel structures and is aligned with the design provisions in the 2021 AISC Specification for Structural Stainless Steel Buildings. It applies to the design of structural hot-rolled or welded open sections such as I-shaped members, channels, and equal-leg angles. It also applies to rectangular and round hollow structural sections (HSS). The guidance provided is applicable to austenitic, duplex, and precipitation hardening stainless steel structural sections with thickness 8 in. and greater. Major topics covered are material behavior and selection, cross-section design, member design, connections, and fabrication. Dimension and property tables are included as well as design tables covering available strength for flexural and compression members and connections. Design examples are also included.

Date: April 2022
Provider: American Institute of Steel Construction

In response to a growing need for high performance, sustainable materials in the built environment, two new AISC standards, and a new edition of AISC Design Guide 27, are now available: Code of Standard Practice for Structural Stainless Steel Buildings (AISC 313-21) Specification for Structural Stainless Steel Buildings (ANSI/AISC 370-21) Structural Stainless Steel, 2nd Edition (AISC Design Guide 27) This session will describe the relationship of the new stainless steel Specification and Code to the existing publications for carbon steel. The primary differences between the Code in Stainless Steel (AISC 313) and the Code in Carbon Steel (AISC 303) will be covered using examples from both architectural and industrial applications. Guidance on how to select an appropriate stainless steel alloy for a specific project will be given and best practice fabrication procedures will also be presented.

Speakers: Catherine Houska; Michael Mulhern, PE

This presentation will introduce the new specification AISC 370, explaining why it is needed and how the mechanical and physical properties of stainless steel differ from those of carbon steel. The structural performance of stainless steel will be compared to that of carbon steel, both at ambient temperatures and in fire, highlighting the key differences in the design provisions in AISC 370 to those in AISC 360. Additional useful information for designers in the new edition of AISC DG27 Structural Stainless Steel will also be presented.

Webinar presented by Nancy Baddoo from the Steel Construction Institute. The webinar touches upon typical applications, properties, grade selection, structural design of members and connections, fire resistance and resources for engineers.

Provider: Steel Construction Institute

Information sheet on stainless steel for structural members in bridges. The leaflet gives essential information for designers and outlines the benefits of using stainless steel in these applications, illustrated by case studies. Two versions are available - one refers to EN standards, and one to US standards.

Date: December 2021
Provider: Steel Construction Institute

Design of stainless steel bridges - EN version
Design of stainless steel bridges - US version

This resource lists the range of available stainless steel section shapes and sizes available in Germany. It also references delivery standards, edge design, finish, grades, Products covered include flat and round bars, rectangular, hexagonal and double-T profiles, flats, squares, angles, channels, T-profile, round tubes, square tubes and rectangular tubes and reinforcing steel. Also covered: masonry sections, facade profiles, window profiles, door frame, railing systems, stair rails, anchor rails. It includes as an annex the German Technical Approval Sonderdruck 862 - Allgemeine bauaufsichtliche Zulassung Z-30.3-6 vom. 5 Dezember 2003.

Date: 2010
Provider: Informationsstelle Edelstahl Rostfrei

This resource is the second edition of an excel spreadsheet prepared by the BSSA specifying all the available stainless steel product forms in the UK. The section categories are: I-Beam Section, H Section, T-Profile (equal and unequal), Z-Profile, Angles (equal and unequal), Channels, Circular Hollow Section, Square Hollow Section, Rectangular Hollow Section, Cold Formed Hollow Section and Special Section.

Date: 2008
Provider: British Stainless Steel Association

This downloadable comprehensive stainless steel library includes a collection of over 280 pdfs and was developed for firms in the architecture, building and construction industry. The information is categorized based on six primary topic areas:

• Alloy Selection and Specification
• Applications
• Fabrication/Cleaning
• Finishes
• Structural Design
• Sustainability and Health.

Subfiles further categorize the information by topic. In addition to brochures, articles, and case studies, there are current specification and guideline and international finish supplier lists.

Date: 2014
Provider: International Molybdenum Association

This resource is a short article comparing the behaviour and mechanical properties of stainless steel and carbon steel. Both stress-strain graphs are presented illustrating how stainless steel has a less defined yield stress. A table also summarises tensile strength, Young’s Modulus and elongation for grades 1.4301, 1.4401, S275 and S355.

Date: 2000
Provider: British Stainless Steel Association

This resource is part 3 of the Structural Stainless Steel Design Manual. It provides commentary on the recommendations from part 1.

Date: 2018
Provider: Steel Construction Institute

Architectural and engineering firms are increasingly exploring stainless steel's possibilities as a structural material as new research, structural codes, and design guides become available. Most designs have used the familiar types 304L or 316l alloys from the austenitic family of stainless steels, but for all the lightest sections, the duplex stainless steel family presents a much greater potential for innovation. Many architects and engineers are unaware of this interesting stainless steel alloy family.

Date: 2015
Provider: The Construction Specifier

This resource is part of the design standard SABS 0162. It applies to the design, based on limit-states, of structural members of cold-formed stainless steels (austenitic and ferritic type 3CR12) sheet, strip or plate up to 25mm in thickness, intended for load carrying purposes in buildings. Supplementary standards can be used for applications other than buildings.

Date: 1997
Provider: South African Bureau of Standards

This resource provides the design criteria for the determination of strength of stainless steel members and connections for use in buildings and other statically loaded structures in the US. It includes the load and resistance factor design (LRFD) method and the allowable stress design (ASD) method. Members can be cold formed to shape from annealed and cold rolled sheets, strips, plates or flat bar material.  Austenitic grades (201, 301, 304, 316 and ‘Nitronic 30’) are covered, in the annealed and cold rolled condition. Ferritic grades (409, 430, 439) are also covered in the annealed condition only.

Date: 2002
Provider: American Society of Civil Engineers

The need for structures –typically bridges and piers – that last one hundred years or more with little or no maintenance rather than the much shorter design life used so far is now widely accepted as cost saving for the community. Stainless steel reinforcing bar in concrete is increasingly used as a straightforward and reliable way to resist corrosion and to provide the adequate service life. You will find either directly or through the references provided the answers to most the questions you may have regarding stainless steel reinforcing bar. The contents have been prepared by an international Task Force of industry experts.

Provider: world stainless association

This brochure provides a handy reference source to help engineers and designers to decide whether to use stainless steel, and, if so, which grade to use. The brochure has chapters dealing with a wide range of relevant topics, from abrasion resistance to fire resistance and further on to mechanical and physical properties. The publications to which it refers can be downloaded from links provided in the brochure.

Date: 2020
Provider: world stainless association

The use of stainless steel rebar in concrete is becoming more important today. Stainless steel provides long and maintenance-free life of structures, as it resists corrosion from aggressive environments. Cedinox just published a book which presents scientific research techniques as well as case studies of applications of stainless steel reinforced concrete.

Date: November 2013
Provider: Cedinox

Technical paper from the cement together with the stainless steel industry, describing the advantages of stainless steel reinforced concrete. 

Date: 2013
Provider: infociments

This publication is written for designers and owners of biogas plants and gives information on the design, fabrication and installation of stainless steel biodigester tanks. Much of the information in the brochure was developed during the EU’s Research Fund for Coal and Steel project: Innovative and competitive solutions using stainless steel and adhesive bonding in biogas production (BIOGASS). This was a three year research project which was completed in 2016. The project partners included stainless steel producers, research institutes, universities and a tank manufacturer. Through experimental tests, field trials and numerical analysis, the project generated design guidance for a range of grades of stainless steels which are suitable for application in biodigesters.

Date: May 2016
Provider: Steel Construction Institute

This training programme (10 short and informative modules) has been designed for students and lecturers of architecture and civil engineering, but can be of interest to all who want to learn about stainless steels. The programme is informative and entertaining and does not require any specific prior knowledge. Links for references are provided.

The training programme is available in Chinese, English, French, Italian, Japanese, Portuguese and Spanish.

Provider: world stainless association

Despite many attractive characteristics, ferritic stainless steel is currently under-used in the construction industry due to a lack of reliable information relating to structural behaviour. A three year pan-European project was completed in 2014 which studied the structural performance of ferritic stainless steels. The objectives of the project were:

• To develop Eurocode-aligned structural guidance for ferritic grades not previously studied but which were identified as being appropriate for structural use;
• To study construction-relevant aspects of structural design and corrosion resistance which have not been studied before (e.g. the performance of structural joints, structural fire resistance, corrosion performance of welded and bolted joints etc.); and
• To examine the structural performance and temperature regulation effects of ferritic stainless steel decking in a composite floor system.

The SAFSS project, which included material and member testing as well as analytical and numerical studies, provided practitioners with useful performance data and design guidance so that ferritic stainless steels can be specified in structures with confidence. The project was, in general, limited to developing guidance relevant to these applications involving material less than 6 mm thick in both welded and bolted construction. Five ferritic grades were studied, with varying levels of corrosion resistance (and cost).

This project was carried out with financial support from the Research Fund for Coal and Steel of the European Community and the International Chromium Development Association.

For more information, please contact Nancy Baddoo at the Steel Construction Institute (N.Baddoo@steel-sci.com)

This information sheet is written for engineers and architects and gives guidance on the structural design of ferritic stainless steels. Much of the information was developed during the EU’s Research Fund for Coal and Steel project Structural Applications of Ferritic Stainless Steels (SAFSS). This was a three year research project which was completed in 2013. The project partners included stainless steel producers, research institutes, universities and design consultants. Through experimental tests, field trials and numerical analysis, the project developed design guidance for a group of ferritic stainless steels which are suitable for structural applications.

Date: April 2014
Provider: Steel Construction Institute

This resource is a design guide aimed at engineers with structural design experience using carbon steel but not necessarily with stainless steel. The guidance covers mechanical and physical properties, design strength, a grade specification guide, member design, connections, fabrication and fire resistant design. A comprehensive set of design tables is included giving gross and effective section properties, section classification and member capacities covering CHS, RHS, SHS, channels, double channels back to back and equal angles back to back. The recommendations have been harmonized with BS 5950-1:2000 and EN 1993 -1-4 whenever appropriate. The grades covered are: austenitic grades EN 1.4301 (304), 1.4401 (316) and the low carbon variants and the duplex grades EN 1.4362 SAF 2304) and 1.4462 (2205). Finally, design examples are presented to demonstrate these design recommendations.

Date: 2001
Provider: Steel Construction Institute

Information sheet on stainless steel for structural members in offshore structures. The leaflet gives essential information for designers and outlines the benefits of using stainless steel in these applications, illustrated by case studies. Two versions are available - one refers to EN standards, and one to US standards.

Date: December 2021
Provider: Steel Construction Institute

Design of stainless steel offshore structures - EN version
Design of stainless steel offshore structures - US version