11 December 2025

Differences Between European and American Standards in the Steel Pipe Industry

In steel pipe trading, it is very common to encounter customers requesting “EN,” others asking for “API 5L,” and others referring to “ASTM A106” or “ASME.”At first glance, these may appear to be different codes for the same type of product, but in reality, they represent two completely different standardization systems: the European system (EN) and the American system (API / ASME / ASTM).

For suppliers and project engineers, understanding these differences ensures correct offers, reduced risks, and projects delivered in full compliance with technical requirements.

1. Two Worlds of Standards: Europe vs. USA

1.1. European Standards (EN)

In Europe, standards are unified under the EN (European Norm) prefix.They cover a wide range of fields, including structural applications, pressure systems, industrial installations, energy, and infrastructure.

Typical examples in the steel pipe sector:

EN 10219 – welded, cold-formed structural hollow sections (square, rectangular, circular).
EN 10210 – hot-finished structural hollow sections.
EN 10216 / EN 10217 – pipes for pressure purposes: seamless (10216) and welded (10217).

An EN standard typically defines:

the steel grade used (S235, S355, P235, P265, etc.)
the intended application (structural, pressure, high temperature)
delivery conditions and testing requirements

1.2. American Standards – Not Only API

In the American system, responsibilities are divided between several major organizations:

API (American Petroleum Institute) – standards for the oil & gas industry, mainly line pipes and well casing/tubing (e.g., API 5L, API 5CT).
ASME (American Society of Mechanical Engineers) – design and construction codes for boilers, pressure vessels, and nuclear installations, mainly through the ASME Boiler and Pressure Vessel Code (BPVC).
ASTM (American Society for Testing and Materials) – material specifications defining chemical composition, mechanical properties, and testing methods (e.g., ASTM A106 seamless high-temperature pipe).

In short:

EN = one unified European system
USA = multiple interconnected standards (API + ASME + ASTM)

2. What EN, API, ASME and ASTM Actually Cover

EN – The “All-Round” European Standard

EN standards define:

the product type (structural, pressure, installations)
the steel grade and its properties
delivery and testing conditions
documentation requirements (EN 10204 3.1 / 3.2 certificates)

Example: EN 10219 S355J2H – welded, cold-formed structural hollow section used in steel structures, halls, and fabrications.

API – The Oil & Gas Pipeline Standard

API 5L is the best-known API standard for pipes, defining seamless or welded pipes used for long-distance petroleum and gas transportation, both onshore and offshore.

steel grades: B, X42, X52, X60, X65, X70, X80, etc.
requirements for mechanical strength, toughness, additional testing (PSL1/PSL2, Charpy impact)
options for aggressive environments (HIC, SSC, sour service)

API is not a generic “pipe standard”; it is specifically designed for pipeline systems operating under demanding conditions.

ASME – The Pressure Design Code

The ASME Boiler and Pressure Vessel Code (BPVC) does not only define materials; it governs the entire design and fabrication framework, including:

boilers
pressure vessels
nuclear installations
heat exchangers and industrial pressure equipment

Materials used in ASME BPVC are often ASTM-based (e.g., ASME SA106 is equivalent to ASTM A106).

ASTM – The “Language of Materials” in the American System

ASTM defines:

chemical composition
mechanical properties
testing methods
general application scope

Example: ASTM A106 – seamless carbon steel pipe for high-temperature service, used in steam systems, thermal oil circuits, and industrial processes.

A fully American-specified project will often include a combination of standards:ASME for design, ASTM for the material, and API for pipeline application (when applicable).

3. Philosophy Difference: “Product Standard” vs. “Ecosystem of Codes”

3.1. EN – Product + Application in One Standard

A typical EN standard indicates:

the type of product (e.g., welded structural hollow section)
the material designation (S355J2H, P235GH, etc.)
required tests
quality documentation

It is a compact system: once the specification reads “EN 10219 S355J2H,” both supplier and engineer know exactly what is required.

3.2. The American System – Standards Working Together

In the U.S. framework:

ASTM defines what steel you use (A106, A53, A333, A312, etc.)
ASME defines how you use it in pressure systems (thickness formulas, design rules)
API defines what the pipe must meet in pipeline service (API 5L, 5CT)

Therefore, when a customer provides a “100% American specification,” it actually references multiple standards at once.

4. EN vs. American “Equivalents” – How Far Can We Go?

Customers often ask:“Is EN 10219 S355J2H equivalent to an ASTM material?”or “Can P265GH be supplied as A106?”

The correct answer:

There are similar performance ranges and comparable applications.
There are no true 1:1 equivalences guaranteed by any standard.
Any substitution must be approved in writing by the project engineer or client.

Examples of approximations (not automatic substitutions):

EN 10219 S355J2H ↔ ASTM A500 Grade C (similar structural purpose).
EN 10216-2 P265GH ↔ ASTM A106 Grade B (both used for high-temperature pressure applications, but with different testing requirements).

In quotations, the safest approach is:

Clearly state the standard required in the RFQ.
When proposing an alternative, label it explicitly as “technical alternative – subject to client approval.”

5. Impact on Pricing and Commercial Discussions

For distributors and traders, the specified standard affects:

price level – API, ASME, and ASTM (with additional testing) are generally more expensive than standard EN materials;
documentation requirements – EN 10204 certification vs. ASME/API stamps and approvals;
tender eligibility – some tenders require exclusively “API/ASME,” others strictly “EN + PED.”

For clients, the standard guarantees that:

the pipe complies with the legislation of the installation country;
the designer has defined a specific safety and mechanical performance framework.

6. Conclusion

European EN standards form a unified system covering structural, installation, and pressure applications across the European industrial landscape.

American standards (API / ASME / ASTM) form an interconnected ecosystem primarily oriented toward oil & gas, pressure vessels, and critical industrial applications where design and material regulations operate in parallel.

The two standardization systems do not overlap perfectly; similarities exist, but no automatic equivalence is recognized. Any substitution must undergo proper technical validation.

7. Technical Support and Product Supply – Titan Steel Trading

If your project requires pipes compliant with EN, API, ASME, or ASTM standards, it is essential to work with a supplier who fully understands the technical distinctions and compliance requirements. Whether you need structural pipes, pressure pipes, pipeline material, or industrial tubing, correct material selection prevents design errors, additional costs, and non-conformities during execution.

Titan Steel Trading provides technical guidance and tailored solutions, including:

correct selection of standards and materials;
alternative technical proposals where allowed;
EN 10204 3.1 / 3.2 certified products;
availability across EN, API, ASME, and ASTM categories.

If you require assistance choosing the right products or would like a customized quotation, feel free to contact us anytime. We are ready to support your procurement process with technical expertise and transparent communication.

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