ASTM vs EN vs JIS vs GB: How Steel Standards Compare

ASTM, EN, JIS and GB specify steel products in different ways. Although their grades may have similar strength or applications, they can differ in chemical composition, dimensions, manufacturing methods, testing and certification.

A steel grade comparison chart can identify possible alternatives, but it cannot approve a substitution. Buyers must compare the complete product requirements and follow the governing project specification.

What Are ASTM, EN, JIS and GB Steel Standards?

Each system has its own naming and classification rules.

ASTM publishes separate specifications for different products. ASTM A36 covers structural steel, ASTM A53 covers general mechanical and pressure pipe, while ASTM A106 covers seamless carbon steel pipe for high-temperature service. The standard number does not indicate strength, so buyers must also specify the grade.

EN designations often contain more information. In P265GH, “P” indicates pressure-purpose steel, “265” refers to a yield-strength level and “GH” identifies elevated-temperature properties. Structural grades such as S355J2 follow a similar system.

JIS uses product-specific prefixes. SS400 is a structural steel, SGP is used for ordinary piping, STPG covers pressure pipe and STPT covers elevated-temperature pipe.

Chinese standards use several naming methods. Q235 and Q355 refer to yield-strength levels, while composition-based grades such as 15CrMoG identify important alloying elements. GB generally identifies mandatory national standards, whereas GB/T identifies recommended national standards. A GB/T standard can still become contractually binding when referenced by a project specification.

For more detail on common ASTM pipe specifications, see Baolai’s ASTM steel pipe standards guide.

How Do ASTM, EN, JIS and GB Standards Differ?

The main differences extend beyond grade names.

A material standard and a dimensional standard do different jobs. ASTM A106 defines the pipe material and manufacturing requirements, while ASME B36.10M commonly provides pipe dimensions.

An EN or JIS pipe may use a different outside diameter, wall thickness or tolerance. Similar material properties therefore do not guarantee that the pipe will fit the same valves, flanges or fittings.

Which Steel Grades Are Commonly Compared?

The following tables show grades often grouped in international steel grade comparison charts. They should be treated as comparison starting points rather than direct equivalents.

Structural steel grades

A36, S235JR, SS400 and Q235B have overlapping structural applications, but their chemistry, thickness-dependent strength and impact requirements differ.

Suffixes are important. S235JR, S235J0 and S235J2 specify different impact-test temperatures. Q235A, B, C and D also represent different quality levels. These suffixes should not be removed from a purchase specification.

General and pressure pipe standards

These standards must be compared by product and service. EN 10217 covers welded pressure tubes, while EN 10216 covers seamless pressure tubes. JIS G3452 SGP is intended for ordinary piping, whereas JIS G3454 and G3456 address pressure or elevated-temperature applications.

The appropriate Chinese standard also depends on service. GB/T 8163 may be used for seamless fluid pipe, while high-pressure boiler service can require GB/T 5310 and a boiler-grade material.

Alloy and stainless steel pipes

Even when nominal compositions are close, product standards may require different heat treatment, dimensional tolerances, testing and delivery conditions.

Why Does Equivalent Not Mean Interchangeable?

“Equivalent” usually means that two grades have broadly similar characteristics. “Interchangeable” means the proposed material satisfies the requirements of a particular project.

The following items must be reviewed:

An MTC verifies the delivered heat against its declared standard. It does not independently prove that the material is an approved substitute for another specification.

How Should Buyers Verify a Cross-Standard Substitute?

1. Confirm the governing specification

Identify the design code, product standard, edition, local regulation and client requirements. The original specification takes priority over a general comparison chart.

2. Match the product and manufacturing method

Compare pipe with pipe and plate with plate. For pipes, confirm whether the project requires seamless, ERW, HFW, LSAW or SSAW production.

3. Compare material properties

Review the full chemical limits, yield strength, tensile strength, elongation and impact performance. Use values for the actual thickness and delivery condition.

4. Check dimensions and heat treatment

Confirm outside diameter, wall thickness, tolerances, end preparation and connection method. Normalized, quenched-and-tempered and solution-annealed materials must also be distinguished.

5. Review testing and documentation

State the required hydrostatic testing, NDT, inspection certificate and traceability documents in the purchase order. Heat numbers on the material should match the MTC.

Independent verification can be arranged through third-party inspection.

6. Obtain written approval

The responsible engineer, owner or authorized technical party should approve any change to the specified standard or grade. The approval should identify the proposed material and any additional testing required.

Source Multi-Standard Steel Products from Baolai

Baolai Group has manufactured and supplied industrial steel pipes since 1991. We provide seamless steel pipes and welded steel pipes in different grades, dimensions and finishes for projects using ASTM, EN, JIS and GB specifications. Send us your required standard, grade, size and quantity for a quotation. 

FAQs

Can one steel pipe comply with both ASTM and EN standards?

Yes, dual certification is possible when the pipe satisfies the material, manufacturing, dimensional and testing requirements of both standards. Both specifications should be stated on the purchase order and MTC.

What does “M” mean in ASTM A53/A53M?

The “M” indicates that the specification includes SI units. ASTM A53/A53M contains both inch-pound and metric requirements; it does not identify a separate steel grade.

Why do similar steel grades have different prices?

Prices can differ because of alloy content, production method, heat treatment, testing, certification, dimensional availability and regional supply. A grade requiring additional impact testing or NDT will usually cost more.

Can ASTM material be supplied with an EN 10204 3.1 certificate?

Yes. EN 10204 3.1 defines the type of inspection document rather than the material standard. ASTM material can be supplied with a 3.1 certificate when specified in the order, but the certificate does not convert it into an EN-grade product.

Do steel grade equivalency charts need to be updated?

Yes. ASTM, EN, JIS and GB standards are periodically revised. Any comparison should use the editions stated in the project documents rather than relying on an undated chart.

Conclusion

ASTM, EN, JIS and GB grades may have similar properties, but a valid substitution requires more than a matching row in a steel grade comparison chart. Buyers must compare the product scope, manufacturing method, chemistry, mechanical properties, dimensions and testing requirements.

The governing project specification and written engineering approval should always determine whether an alternative material can be used.

Sources and Further Reading

• ASTM Steel Standards
• CEN-CENELEC European Standards
• Japanese Industrial Standards Committee
• National Standards of China