A572 Grade 50 is a common, high-strength, low-alloy (HSLA) structural steel with a minimum yield strength of 50 ksi (50,000 psi), known for its excellent strength-to-weight ratio, making it ideal for bridges, heavy construction, truck frames, and poles, as it provides significant strength in lighter profiles compared to standard A36 steel. It's readily weldable and formable, often replacing older grades, and is used in beams, channels, angles, and plates for demanding applications.
Key Properties
Yield Strength: Minimum 50 ksi (50,000 psi)
Tensile Strength: Minimum 65 ksi (65,000 psi)
Type: High-Strength Low-Alloy (HSLA) Columbium-Vanadium Steel
Weldability:
Good, similar to A36 steel
What are the available forms of A572 Grade 50?
A572 Grade 50 is available in a wide range of standard structural and flat-rolled forms, making it one of the most versatile high-strength low-alloy (HSLA) steels for construction and fabrication.
Here are the primary available forms:
1. Structural Shapes
Wide-Flange Beams (W-shapes): The most common form for columns and beams in building frames.
Channels (C-shapes & MC-shapes)
Angles (L-shapes): Equal and unequal leg angles.
Tees (WT, MT, ST): Cut from wide-flange beams or rolled.
HSS (Hollow Structural Sections): Square and rectangular tubing (less common than in ASTM A500, but available per A1085).
2. Flat-Rolled Products
Plates: Available in various thicknesses, commonly from 3/16" (5mm) up to several inches thick. Used for base plates, gussets, and fabricated components.
Sheets & Coils: Thinner gauges for lighter structural members, panels, or forming.
3. Bar Products
Rounds, Squares, and Flat Bars: Used for machining parts, bracing, brackets, and other fabricated elements.
Key Specifications & Context
Governing Standards: The form is dictated by a specific ASTM standard:
Structural Shapes: ASTM A992 (which supersedes A572 Gr. 50 for most W-shapes) is now the predominant standard for wide-flange beams. A572 Gr. 50 is still called out for other shapes.
Plates, Bars, and Sheets: ASTM A572/A572M is the direct standard.
HSS: ASTM A1085 (for HSS) or A500 (though A500 Grade C is more common for tubing).
Commonality: Wide-flange beams (A992, which is chemically and mechanically similar to A572 Gr. 50) and plates are the most widely stocked and used forms.
Availability: It is a mill-produced standard item readily available from major steel producers, service centers, and distributors in North America and globally.
Procurement Tip: When specifying, always state the material grade (A572 Grade 50) and the product form standard (e.g., ASTM A572 Plate, or ASTM A992 for W-beams) to ensure you receive the correct product.
1. What is A572 Grade 50 steel used for?
A572 Grade 50 is commonly used in structural applications like building frames, bridges, transmission towers, and construction equipment where higher strength than A36 steel is needed.
2. What is the yield strength of A572 Grade 50?
The minimum yield strength of A572 Grade 50 is 50 ksi (345 MPa).
3. What is the difference between A572 Grade 50 and A36?
The main difference is strength: A572 Grade 50 has a higher yield strength (50 ksi vs. 36 ksi) and is a high-strength low-alloy (HSLA) steel, while A36 is a mild carbon steel.
4. Can A572 Grade 50 be welded?
Yes, it has good weldability using common methods like shielded metal arc welding (SMAW) and gas metal arc welding (GMAW), though proper procedures should be followed.
5. What is the chemical composition of A572 Grade 50?
It typically contains elements like carbon (max 0.23%), manganese (max 1.35%), phosphorus, sulfur, and may include small amounts of columbium, vanadium, or nitrogen for strengthening.
6. Is A572 Grade 50 corrosion resistant?
No, it is not a corrosion-resistant grade. For outdoor or corrosive environments, it usually requires protective coatings like paint or galvanizing.
7. What are the available forms of A572 Grade 50?
It is widely available in structural shapes (beams, channels, angles), plates, bars, and sheets.
8. What is the equivalent of A572 Grade 50 in European standards?
The closest European equivalent is S355JR or S355J2 according to EN 10025-2, though exact matching depends on thickness and impact requirements.
9. How does A572 Grade 50 compare to A992 steel?
A992 is a newer, more tightly controlled structural steel primarily for wide-flange shapes, with similar yield strength (50-65 ksi) but stricter chemical and mechanical limits.
10. What is the price of A572 Grade 50 compared to A36?
A572 Grade 50 typically costs 10-25% more than A36 due to its higher strength and alloy content, but prices vary with market conditions and order size.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
