SteelWhat is A572 steel and what is it used for? High-strength structural steel (HSLA)
A572 steel is high-strength structural steel (HSLA). In this guide we explain what A572 steel is, its composition, its properties, what it is used for and the sizes we stock.
What is A572 steel?
Family of high-strength, low-alloy (HSLA) structural steels (ASTM A572 / A572M), with minimum yield strengths between 290 and 450 MPa. Microalloyed with niobium, vanadium, titanium, or nitrogen; high strength-to-weight ratio, good weldability, and easy fabrication. For welded, bolted, or riveted structures, buildings, towers, platforms, frames, and heavy machinery.
Chemical composition of A572 steel
This is the typical composition of A572 steel (ASTM A572 Gr. 50 / EN S355JR / DIN 1.0045 / JIS SM490 standard):
| Element | Contents | What for? |
|---|---|---|
| Carbon (C) | 0.26 % max. | Adds strength; limited to preserve weldability |
| Manganese (Mn) | 1.65 % max. | Adds strength and hardenability |
| Silicon (Si) | 0.40 % max. | Deoxidizer |
| Phosphorus (P) | 0.040 % max. | Impurity, kept low |
| Sulfur (S) | 0.050 % max. | Impurity, kept low |
A572 grades and properties
A572 is a high-strength low-alloy (HSLA) steel. It comes in grades defined by yield strength (42, 50, 55, 60 and 65 ksi; grade 50 is the most widely used, at 345 MPa). It is microalloyed with niobium, vanadium or titanium to achieve a high strength-to-weight ratio: it holds more with less weight, while retaining good weldability. Ideal for structures where saving weight without losing strength matters.
What is it for? Applications of A572
A572 steel is mainly used in:
- Steel structures
- Industrial buildings
- Bridges and walkways
- Structural towers
- Industrial platforms
- Machinery frames
- Cranes and heavy equipment
- High-load supports
- Welded structural components
Forms and sizes we carry
At NAT MAC we stock A572 steel in these forms and sizes:
| Package size | Sizes |
|---|---|
| Plates | 3/16" – 4" (4.76 – 102 mm) |
| Flat bars | Made to length |
If you need a particular size, tell us which one and we will gladly source it for you.
A572 equivalents and standards
A572 steel is also identified by these standards: ASTM A572 Gr. 50 / EN S355JR / DIN 1.0045 / JIS SM490. You can see how to read them in our article on steel standards.
In summary
- A572 is a high-strength low-alloy (HSLA) steel, grades 42 to 65
- Microalloyed; high strength-to-weight ratio and good weldability; grade 50 is the most widely used
- For structures, buildings, towers, bridges and heavy machinery
- We carry it in plates, flat bars, cut to size
Why buy your A572 steel at NAT MAC?
We have more than 54 years of experience as an industrial supplier and ISO 9001 certified quality. We carry quality structural plate and help you choose the right grade for your project.
- Quality A572 steel plate, with backing and traceability
- Material cut to the size you need
- Technical advice on choosing the right structural steel
- Wide range of structural plate in stock
- On-time deliveries and competitive prices
Tell us what you will make and in what sizes, and we'll recommend the right grade and form. Request your free quote.
Sources: data sheet from our NAT MAC catalog (composition, sizes and applications) and the corresponding ASTM standards. Values are for reference and may vary by grade, standard and heat.
