A913 steel sections are manufactured using a Thermo-Mechanical Controlled Rolling Process (TMCP) and a Quenching and Self-Tempering (QST) process to attain superior strength and weldability, while preserving the requisite ductility for contemporary structures. Notably, both processes seamlessly integrate into the production line, ensuring no extra lead time in comparison to alternative steel grades.

A913 achieves its heightened strength from additional grain refinement introduced during the QST process. In this method, hot steel sections (approximately 1600 F) are subject to swift, controlled cooling (quenching), which is halted before the cross-section's core is entirely affected. The residual heat within the core facilitates self-tempering as it migrates from the core to the surface.

This distinctive process sets A913 steel apart from other steels that rely on conventional alloying for strength enhancement. This enables A913 to uphold ductility and weldability characteristics that are at par with or even surpassing those of A992 steel. Consequently, engineers find A913 steel easy to integrate into their designs.

If a section is strength-controlled and exceeds a weight of approximately 100 lbs/foot, there is an opportunity to reduce both weight and costs by incorporating A913. In fact, the adoption of grade 80 in the design process can yield weight savings exceeding 30%, as illustrated.

This weight reduction is particularly advantageous in heavily loaded structures, including high-rise buildings, stadiums, multi-story hospitals, laboratories, manufacturing facilities, and braced framed systems in seismic areas, among others. These projects often necessitate the use of the heaviest rolled shapes, sometimes surpassing the capacities of even the largest A992 rolled sections. The integration of A913 can mitigate the costs associated with the heaviest sections or eliminate the need for intricate fabrication solutions such as built-up columns or cover plates on rolled shapes.

Further, weight reduction has compounding benefits for the whole project. A smaller section with thinner webs and flanges results in less weld volume and fewer weld passes. In addition, smaller sections improve constructability by alleviating crane loads and simplifying erection procedures.

A913 steel exhibits superior welding characteristics compared to A992 steel. Its strength, derived from the QST process rather than alloying elements, translates to lower carbon and carbon equivalent values compared to A992.

This attribute of A913 results in enhanced resistance to cracking and reduces or eliminates the need for preheating the member prior to welding. The ability to weld without preheating represents a substantial cost-saving advantage for both fabrication and erection.

Effective with the release of AWS D1.1 2025, all grades of A913 steel are classified as prequalified base metals, thus streamlining the overall welding process. The corresponding prequalified minimum preheat temperatures can be found in the table below and here.

Unlike A992, Charpy V-Notch (CVN) testing of A913 is not a supplementary requirement. The A913 specification includes a minimum CVN absorbed energy value of 40 ft-lbf at 70°F for all sections in the standard flange location.

Upon agreement, A913 sections meeting a CVN requirement of 20 ft-lbf at 70°F at the alternate core location (S30) can be provided. This value is required by AISC 360 Section A3.1 for steel used in tensile applications featuring flange thickness exceeding 2 in., and AISC 341 Section A3.3 for steel used in seismic force resisting systems featuring flange thicknesses exceeding 1-1/2 in.

For information on capabilities for other CVN test requirements, including cold weather applications, please contact us.

A913 steel has been an approved material specification by AISC since 1995. This acceptance was first reflected in the 1999 version of AISC 360. Today, all A913 grades are included in the AISC 360 specification as approved materials and can be used with the same phi factors and design limits as any other material in the code.   

A913 Grades 50, 65, and 70 are included in AISC 341 for specific applications. See “Seismic Applications” for further details. 

All of ArcelorMittal's A913 shapes are produced at our Differdange mill in Luxembourg, which is equipped with our quenching and self-tempering (QST) technology The QST process used to produce A913 shapes is an in-line process, meaning the steel will not leave the production line to receive the treatment. As a result, it is an inherently efficient, performance-enhancing treatment method. Consequently, there is no difference in lead time by specifying A913 over a comparable A992 shape.

In addition, because QST is an in-line process, A913 will follow the same rolling schedule as A992. Therefore, if a shape is scheduled to be rolled, the customer can easily indicate what specification is desired. Further, most of our sections with A913 availability are rolled every 3-6 weeks, at minimum.

See our full list of A913 shape and grade availability here or refer to Product and Size Range page.