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
Architects | Jan 4, 2021
Moody Nolan receives 2021 AIA Architecture Firm Award
Founded by Curt Moody, FAIA, NOMA, and the late engineer Howard E. Nolan, the firm’s work is centered on the belief that diverse perspectives foster creativity and more responsive solutions.
AEC Tech | Dec 17, 2020
The Weekly show: The future of eSports facilities, meet the National Institute for AI in Construction
The December 17 episode of BD+C's The Weekly is available for viewing on demand.
Multifamily Housing | Dec 16, 2020
What the Biden Administration means for multifamily construction
What can the multifamily real estate sector expect from Biden and Company? At the risk of having egg, if not a whole omelet, on my face, let me take a shot.
Giants 400 | Dec 16, 2020
Download a PDF of all 2020 Giants 400 Rankings
This 70-page PDF features AEC firm rankings across 51 building sectors, disciplines, and specialty services.
Architects | Dec 14, 2020
2021 AIA Gold Medal awarded to Edward Mazria
The Gold Medal honors an individual whose significant body of work has had a lasting influence on the theory and practice of architecture.
Healthcare Facilities | Dec 10, 2020
The Weekly show: The future of medical office buildings, and virtual internship programs
This week on The Weekly show, BD+C editors spoke with leaders from SMRT Architects and Engineers and Stantec about the future of medical office buildings, and virtual internship programs
Multifamily Housing | Dec 4, 2020
The Weekly show: Designing multifamily housing for COVID-19, and trends in historic preservation and adaptive reuse
This week on The Weekly show, BD+C editors spoke with leaders from Page & Turnbull and Grimm + Parker Architects about designing multifamily housing for COVID-19, and trends in historic preservation and adaptive reuse
Giants 400 | Dec 3, 2020
2020 Science & Technology Facilities Giants: Top architecture, engineering, and construction firms in the S+T sector
HDR, Jacobs, and Turner head BD+C's rankings of the nation's largest science and technology (S+T) facilities sector architecture, engineering, and construction firms, as reported in the 2020 Giants 400 Report.
Giants 400 | Dec 3, 2020
2020 Laboratory Facilities Sector Giants: Top architecture, engineering, and construction firms in the U.S. laboratory facilities sector
Affiliated Engineers, HDR, and Skanska top BD+C's rankings of the nation's largest laboratory facilities sector architecture, engineering, and construction firms, as reported in the 2020 Giants 400 Report.
Giants 400 | Dec 3, 2020
2020 Industrial Sector Giants: Top architecture, engineering, and construction firms in the U.S. industrial buildings sector
Clayco, Jacobs, and Ware Malcomb top BD+C's rankings of the nation's largest industrial buildings sector architecture, engineering, and construction firms, as reported in the 2020 Giants 400 Report.