ASTM A572 Steel Grades Explained: Mechanical Properties, International Equivalents & Buying Guide

ASTM A572 steel is a high-strength low-alloy (HSLA) structural steel specification used in buildings, bridges, machinery and other structural applications. It covers Grades 42, 50, 55, 60 and 65, with different strength and chemical composition requirements.

This guide covers ASTM A572 equivalent grades, A572 steel properties, yield strength, chemical composition and purchasing considerations to help buyers select the right material.

ASTM A572 Quick Reference

• Steel type: High-strength low-alloy structural steel.
• Grades: A572 Grade 42, 50, 55, 60 and 65.
• Common Grade 50 comparisons: S355JR, Q345B and Q355B, subject to verification against the applicable standards.
• Before ordering: Confirm grade, product dimensions, mechanical properties and material test documentation.

ASTM A572 Equivalent Grades

The following table lists grades commonly compared when sourcing ASTM A572 equivalent materials. These are comparison candidates, not guaranteed direct equivalents.

ASTM A572 Grade	Commonly Compared Grade	Standard
Grade 42	S275JR	EN 10025-2
Grade 42	SM400A / IS 2062 E250	Applicable JIS / IS standards
Grade 50	S355JR	EN 10025-2
Grade 50	Q345B / Q355B	Applicable GB standards
Grade 50	SM490A / IS 2062 E350	Applicable JIS / IS standards
Grade 60	S420-series grades / SM490YA	Verify the specific standard and grade
Grade 65	S460-series grades / SM490YB	Verify the specific standard and grade

ASTM A572 Grade 50 equivalent: S355JR, Q345B and Q355B are commonly considered during material sourcing because of their structural applications and strength levels. However, their chemical composition, impact requirements, dimensions and other standard requirements differ.

Before substituting materials, compare the applicable standards and confirm that the proposed grade meets the project requirements.

ASTM A572 Mechanical Properties and Yield Strength

The mechanical properties of ASTM A572 steel vary by grade. The table below summarizes the specified minimum yield and tensile strength values listed in ASTM A572/A572M reference editions. Confirm the applicable edition and product requirements before using these figures for design or procurement.

Grade	Minimum Yield Strength	Minimum Tensile Strength	Typical Application Context
A572 Grade 42	290 MPa (42 ksi)	415 MPa (60 ksi)	Structural applications specified for this grade
A572 Grade 50	345 MPa (50 ksi)	450 MPa (65 ksi)	General structural fabrication
A572 Grade 55	380 MPa (55 ksi)	485 MPa (70 ksi)	Structures designed for this strength level
A572 Grade 60	415 MPa (60 ksi)	520 MPa (75 ksi)	Higher-strength structural applications
A572 Grade 65	450 MPa (65 ksi)	550 MPa (80 ksi)	Applications requiring higher specified strength

These are reference minimum values, not tensile-strength ranges. Verify the applicable ASTM A572/A572M edition, product form, dimensions and grade-specific requirements before ordering.

ASTM A572 Chemical Composition

The table below summarizes key ASTM A572 chemical composition requirements from ASTM A572/A572M-21. Values are heat-analysis limits in weight percent (%); product dimensions and specific standard provisions affect which limits apply.

Grade	Carbon, Max.	Manganese, Max.	Phosphorus, Max.	Sulfur, Max.	Silicon
A572 Grade 42	0.21%	1.35%*	0.030%*	0.030%*	Max. 0.40% or 0.15–0.40%
A572 Grade 50	0.23%	1.35%*	0.030%*	0.030%*	Max. 0.40% or 0.15–0.40%
A572 Grade 55	0.25%	1.35%*	0.030%*	0.030%*	Max. 0.40% or 0.15–0.40%
A572 Grade 60	0.26%	1.35%*	0.030%*	0.030%*	Max. 0.40% or 0.15–0.40%
A572 Grade 65	0.23% or 0.26%**	1.65% or 1.35%**	0.030%*	0.030%*	Max. 0.40% or 0.15–0.40%

* Manganese, phosphorus, sulfur and silicon requirements: Applicable limits and exceptions depend on product type, dimensions and the standard’s provisions. The standard permits manganese adjustments under specified conditions and allows higher phosphorus/sulfur limits for certain product categories.

** Grade 65: The applicable carbon and manganese limits depend on product thickness or size. An alternative chemistry requirement is also permitted under the standard.

The steel also requires specified alloy content involving niobium (columbium), vanadium, titanium and/or nitrogen. Confirm the complete chemistry requirements and actual heat analysis on the material test certificate (MTC) before procurement. Gr.42 and Gr.55 not shown; Gr.42 has lower C/Mn, Gr.55 is intermediate. Full data available upon request.*

ASTM A572 Steel Applications

ASTM A572 structural steel is used where its specified strength and product characteristics meet the design and project requirements. Common application areas include:

• Structural fabrication: Building frames, load-bearing components and structural assemblies.
• Bridges and infrastructure: Components specified to meet the applicable design and material requirements.
• Power and industrial facilities: Structural supports and fabricated steel components.
• Machinery and construction equipment: Components designed around specified strength, dimensions and fabrication requirements.

For bridge and highway structures, ASTM A572 is often compared with A709 steel due to differences in toughness requirements and weathering performance. For a detailed comparison and grade breakdown, see our ASTM A709 steel plate grades and applications guide.

6. ASTM A572 Steel Supply & Export Options

Whether you’re a stockist, trading company, or processing workshop, A572 steels provide flexibility for multi-market distribution.

At CJM Steel, we maintain regular stock for A572 Gr.50 / S355JR, with custom rolling available for higher grades like Gr.60 and Gr.65. Our team helps clients match regional equivalents (EN, IS, JIS) and ensures smooth compliance with project specifications.

check our dedicated pages:

• A572 Carbon Steel Plate
• A572 Carbon Steel Coil
• A572 Round Steel Bar
• ASTM A572 Diamond & Tread Checkered Steel Plate

7. Summary: Making the Right Procurement Decision

• ASTM A572 steel grades cover five strength levels: 42, 50, 55, 60 and 65.
• A572 Grade 50 is a common option for general structural applications.
• ASTM A572 equivalent grades should be compared against the applicable standards, not selected by strength alone.
• Before purchasing, verify mechanical properties, chemical composition, dimensions and material certification.