EN 10138 is a European Standard series used to specify and verify prestressing steel products for concrete construction, such as products supplied as wire, strand, or bars (depending on the cited part). It is commonly referenced in structural concrete supply chains where consistent mechanical performance and documented product properties are required.
If you need help matching your material form (wire/strand/bar), acceptance requirements, and the correct EN 10138 part for your project, contact our team and we will help you align the test plan with the designation on your drawings or procurement documents.
EN 10138 — Prestressing steels
EN 10138 is primarily a product requirements/specification framework for high-tensile prestressing steels used in prestressed concrete and related tensile applications in construction. Instead of being a single “bench test method,” it is typically used to define what properties must be met and what verification evidence (tests, inspection, documentation) is needed for the delivered product.
In practice, EN 10138 is used by mills, fabricators, contractors, and test laboratories to confirm that prestressing steel products meet required mechanical and performance characteristics for their intended use.
Quick definition
Standard type: Multi-part product requirements/specification (prestressing steel products).
What it is used for: Defining acceptance requirements and verification expectations for prestressing steel supplied as finished product (the exact product form depends on the cited EN 10138 part).
What it is not: A single standalone laboratory test method; it commonly relies on referenced test methods for how properties are measured.
What this standard covers
EN 10138 addresses requirements for prestressing steel products intended to be tensioned to introduce compressive stress into concrete members. The series is organized into parts, typically including general requirements plus additional parts that focus on specific product forms.
Depending on the part cited, EN 10138 may address items such as: mechanical property requirements, performance-related characteristics (for example, time-dependent behavior), dimensional tolerances, surface condition considerations, and required inspection/testing documentation for product acceptance.
Why this standard matters in testing
Prestressing steel performance is safety-critical: it influences load capacity, serviceability, and long-term behavior of prestressed members. EN 10138 helps procurement and QA/QC teams define measurable acceptance criteria and a consistent compliance pathway for prestressing steels across projects and suppliers.
For laboratories, EN 10138 commonly drives which properties must be demonstrated and how results are documented on certificates or inspection reports (often in combination with project specifications and structural design references).
Common materials, product types, or applications covered
EN 10138 is used in prestressed concrete construction environments where steel is supplied specifically for prestressing operations. Common contexts include infrastructure and building components that use prestressing tendons or bars, and construction systems that require high-tensile steel elements designed to be stressed as part of installation.
Common product forms (by cited part): Prestressing wire, prestressing strand, and prestressing bars are typical categories referenced across the EN 10138 series.
Common test or verification workflow
Because EN 10138 is specification-oriented, a typical compliance workflow includes confirming the correct EN 10138 part, identifying required properties and acceptance thresholds, and then performing or reviewing the required verification tests using referenced test methods.
Common verification activities may include: Mechanical tensile property checks (strength and ductility), dimensional verification, and performance-related checks that are frequently specified for prestressing steel (the exact list depends on the cited part and the product form).
Practical note: Testing scope and sampling frequency are often driven by the product certification route and project specification, not only by the EN 10138 designation alone.
Equipment commonly used for this standard
EN 10138 typically points to equipment used for verification of high-strength steel products rather than a single dedicated apparatus. The exact configuration depends on the product form (wire, strand, bar) and which properties must be demonstrated.
Common equipment families: Universal testing machines (UTMs) sized for high-force steel testing, appropriate grips/fixtures for wire, strand, or threaded/plain bars, axial extensometers (where required by the referenced method), precision measurement tools for diameter/profile, and (when specified) dedicated systems for longer-duration or performance-related checks.
If you are specifying machine capacity, grips, and extensometry for a particular EN 10138 part and product form, you can request a detailed quote for a configuration matched to your specimen geometry and required force range.
How to read this designation or revision
EN 10138 is commonly cited as a series title (“EN 10138”) together with a part number (for example, “EN 10138-1”) that identifies the applicable document for the product form or general requirements. National adoptions often appear with a country prefix (for example, “DIN EN …” or “BS EN …”) while referencing the same EN document.
Revision sensitivity: Test scope, referenced test methods, and reporting expectations can change by edition. For procurement, quoting, and compliance documentation, match the exact cited part number and the dated/undated reference used in the contract documents.
Related standards, methods, or frameworks
EN 10138 is frequently used alongside structural concrete design and execution requirements that reference prestressing steel properties and acceptance documentation. The EN 10138 series may also reference separate test method standards for how to perform the required measurements on prestressing steel products.
Common coordination point: Project specifications may call up EN 10138 for product requirements while separately stating which test methods, inspection certificates, and acceptance documentation must be provided for the delivered prestressing steel.
Talk to a testing specialist
If you need to align an EN 10138 requirement with a lab test setup (capacity, grips, extensometry, and reporting expectations) for your specific prestressing steel product form, talk with our team and we will help map the requirement to a practical verification workflow.