Request a Quote

Message / Order details:

Tel. 416.751.5033
Fax. 416.751.0074
Since 1950


What Are the Different Grades of Steel?

September 25, 2019

There exist an abundance of grades that structural steel fabricators are to be cognizant of when it comes to structural steel production.


The properties of structural steel are directly related to their chemical composition, this is important when fabricating steel to satisfy architectural and engineering demands.


For these reasons, it is appropriate to have a set of defined standards to allow structural steel fabricators to produce steel that meet the strength, anti-corrosion, welding, and economic requirements for unique applications. That is why The American Society for Testing and Materials (ASTM) have outlined a number of specifications surrounding structural steel grades.


Today’s piece will focus on some of the more common steel grades seen in use:



Known for their superior welding and machining applications, this all-purpose structural steel grade saw wide usage in industrial and commercial construction up until the start of the 21st century. However, A36 steel is still commonly used for miscellaneous sections, miscellaneous channels, angles, plates, and bars.



This grade of structural steel is renowned for its anti-corrosion, high-strength, and low-alloy properties.


Adding to this, A588 steel is sought out for its weathering features – this steel grade contains low enough levels of copper capable of producing a thin rust-like film on the steel’s surface as oxidation occurs from atmospheric exposure. This slight layer of rust perturbs continual oxidization, meaning painting is not required.


Caution is advised should this steel be subject to saltwater, water submersion, or arid environments as cyclic dry and wet conditions are required to form the protective layer of rust.



This steel grade is a common choice when utilizing a hollow structural section (such as HSS beams). While this serves to be an important specification for steel in the USA, the Canadian Standards Association (CSA) provides a standard of its own, requiring higher levels of precision, known as CSA G40.21.


Professional Steel Fabrication

We’ve accrued some of the best talent in the industry at Scarboro Steel Works Inc. since our establishment in 1950. As structural steel fabricators, we make sure to never compromise on quality for our clients, no matter the project!