ASTM has released a new HSS standard, A1085 - 13 Standard Specification for Cold-Formed Welded Carbon Steel Hollow Structural Sections (HSS), which will result in the production of improved hollow structural sections (HSS). This specification is a big step forward in simplifying HSS design and usage, thereby making it a more desirable option for HSS.
"We were committed to the development of the new ASTM A1085 specification as it was needed to improve the performance of HSS used in structural applications such as seismic load resisting systems, bridge structures and other dynamically loaded structures," said Brad Fletcher, senior sales engineer with AISC-member Atlas Tube. According to Fletcher, round and square members from 6 in. and up will likely be the main shapes Atlas initially produce under the new specification.
Benefits include:
- Tighter material tolerances and a single minimum yield stress of 50 ksi. Because of the more stringent wall tolerances and the addition of a mass tolerance, it's anticipated that AISC's Committee on Specifications will shortly issue guidelines allowing the full nominal wall thickness can be used for design of HSS. This means no longer needing to reduce the nominal wall thickness by 0.93 as prescribed in the AISC Steel Construction Manual for both member selection and connection design. And more area available for design and a higher minimum yield mean that HSS will become a more economical and efficient design option.
- Maximum specified yield stress of 70 ksi. This will result in a lower expected yield strength for seismic design, and thereby reduce capacity design requirements when HSS are the yielding element. For example, with ASTM A1085 HSS braces in a braced frame, the beams and columns will have lower required strengths. ASTM A1085 is the only HSS specification used in North America or Europe that limits the maximum yield stress.
- Standard requirement for notch toughness. The specification will require all HSS to meet a minimum Charpy V-notch (CVN) value of 25 ft-lb at 40°F, which corresponds to AASHTO Zone 2 requirements. Having the minimum CVN required makes HSS more suitable for use in dynamically loaded structures.
"A1085 makes designing with HSS easier and more efficient for both building and bridge construction," said John Simon, vice president of sales with AISC-member EXLTUBE. "We are hearing a great response from structural engineers who have begun to learn about this new spec through efforts at NASCC: The Steel Conference and other communications, and we're working closely with AISC and the Steel Tube Institute to begin promoting A1085 to our customers. EXLTUBE will be supporting these efforts with inventory as soon as we've determined the sizes the market will require from us."
John Tassone, marketing manager for AISC-member Independence Tube, also commented: "We will be manufacturing and inventorying the product as the need arises," adding that the company will likely concentrate on squares and rounds 4 in. and above to start.
For specific price and availability information, please contact HSS producers and service centers. Contact information is available at www.aisc.org/hss.
About the American Institute of Steel Construction
The American Institute of Steel Construction, headquartered in Chicago, is a not-for-profit technical institute and trade association established in 1921 to serve the structural steel design community and construction industry. AISC's mission is to make structural steel the material of choice by being the leader in structural steel-related technical and market-building activities, including: specification and code development, research, education, technical assistance, quality certification, standardization, and market development. AISC has a long tradition of service to the steel construction industry of providing timely and reliable information.
Related Stories
Building Owners | Oct 12, 2021
6 ways building owners can own their construction projects
Building owners have an important role in executing their capital projects and can greatly increase their project’s chances of success by understanding and actively managing a few key factors.
AEC Tech Innovation | Oct 7, 2021
How tech informs design: A conversation with Mancini's Christian Giordano
Mancini's growth strategy includes developing tech tools that help clients appreciate its work.
Green | Oct 6, 2021
My reaction to the UN IPCC Climate Change 2021 report: Ugh!
The recent report of the UN Intergovernmental Panel on Climate Change is not a happy read.
Sponsored | Glass and Glazing | Oct 1, 2021
Specifying Responsibly to Save Birds’ Lives
Realizing sustainable, bird-friendly glass design
Sponsored | Glass and Glazing | Oct 1, 2021
Seizing the Daylight with BIPV Glass
Glass has always been an idea generator. Now, it’s also a clean energy generator.
Architects | Sep 30, 2021
Riding the great AEC resignation wave
More people than ever are reconsidering what work and career mean. What can AEC firms do to recruit and retain workers in this changing workplace environment? Karl Feldman, Partner with Hinge Marketing, discusses ideas and strategies with BD+C's John Caulfield in this exclusive interview for HorizonTV.
Glass and Glazing | Sep 30, 2021
Plans move forward on Central Place Sydney, duel towers with an AI-driven façade system
SOM and Fender Katsalidis are designing the project.
Architects | Sep 28, 2021
Hoffmann Architects Welcomes Travis Heim as Senior Staff Architect
Hoffmann Architects, an architecture and engineering firm specializing in the rehabilitation of building exteriors, announces that Travis Heim has joined the New York office as Senior Staff Architect.
AEC Business Innovation | Sep 28, 2021
Getting diversity, equity, and inclusion going in AEC firms
As a professional services organization built on attracting the best and brightest talent, VIATechnik relies on finding new ways to do just that. Here are some tips that we’ve learned through our diversity, equity, and inclusion (DE&I) journey.
Multifamily Housing | Sep 22, 2021
Designing for the ‘missing middle’ in multifamily housing
Multifamily housing expert Patrick Winters, AIA, discusses a neglected segment of the market: the "missing middle."