DIN 50138 is a legacy DIN standard for the ring tensile test on metallic tubes. It describes a ring-based tensile evaluation used in tube and pipe testing when a full-length tensile specimen is not practical.
DIN 50138 is withdrawn and is commonly encountered today as a referenced requirement in older product specifications or drawings. If you need help mapping an existing requirement to the correct current standard and test setup, contact our team.
DIN 50138: Testing of Metallic Materials; Ring Tensile Test on Tubes
DIN 50138 (publication date 1979-05) is titled “Testing of Metallic Materials; Ring Tensile Test on Tubes” (German: “Prüfung metallischer Werkstoffe; Ringzugversuch an Rohren”). The document is identified as withdrawn in DIN’s standard record.
In practice, the ring tensile approach is used to stress tube material in the circumferential direction using a ring specimen, often supporting formability and integrity checks for tubes (including welded tubes where the weld area may be of special interest).
Quick definition
DIN 50138 in one line: A withdrawn DIN standard that defines a ring tensile test procedure for metallic tubes using a ring specimen to evaluate mechanical behavior under tensile loading.
Document status: Withdrawn; commonly superseded in modern specifications by later EN/ISO tube test standards.
What This Standard Covers
DIN 50138 covers a tensile test performed on a ring taken from a tube. The intent is to apply tensile loading to the tube material using a ring geometry rather than a conventional straight tensile specimen.
The standard is typically referenced when a requirement specifically calls for a “ring tensile test” on tubing, or when older specifications cite DIN 50138 by number.
Why This Standard Matters in Testing
When DIN 50138 is specified, it can change both specimen handling and fixturing compared with a standard tensile coupon. That affects how a lab sets up the test frame, selects grips/fixtures, and interprets what “pass/fail” means under the cited product requirement.
Because DIN 50138 is withdrawn, the most important practical step is ensuring the correct replacement (or the exact legacy method) is being applied for compliance, audits, or supplier qualification.
Common Materials, Product Types, or Applications Covered
DIN 50138 is used in the context of metallic tubes and pipes. It may appear in older requirements for steel tubing and other metallic tubular products where ring-based tensile evaluation is specified.
Common use cases: Tube and pipe quality evaluation, technology/formability checks, and requirements that focus on tube behavior using a ring specimen (including cases where weld regions are of interest on welded tube products).
Common Test or Verification Workflow
A typical DIN 50138 workflow starts with removing a ring specimen from the tube, then mounting that ring in a dedicated ring tensile fixture and applying tensile loading on a universal testing system.
Common workflow elements: ring specimen preparation from a tube section, fixture alignment, tensile loading under controlled test conditions, and documenting results per the purchasing or product specification that cites DIN 50138.
Revision sensitivity: Because this is a withdrawn legacy designation, acceptance criteria and reporting expectations often come from the product specification that references the standard (or from the specified replacement standard).
Equipment Commonly Used for This Standard
DIN 50138 is primarily equipment-driven by the need to load a tube ring specimen in tension with appropriate alignment and stability.
Common equipment: Universal testing machine (UTM), appropriate load cell capacity, and a ring tensile test fixture designed for tube ring specimens.
When quoting or configuring a system, key practical considerations typically include specimen size range (tube diameter/wall), fixture compatibility with the frame, alignment guidance, and the software/report outputs needed for your internal quality documentation.
How to Read This Designation or Revision
DIN 50138 is commonly cited as “DIN 50138.” DIN’s standard record identifies the specific edition as DIN 50138:1979-05 and shows the document status as withdrawn.
DIN also indicates that DIN 50138 has been replaced by DIN EN 10237:1994-01 and DIN EN ISO 8496:2004-10. If a customer or drawing calls out DIN 50138 without an edition date, confirm whether the intent is to follow the legacy method or to use the cited replacement standard.
Related Standards, Methods, or Frameworks when useful
DIN’s listing for DIN 50138 points to later replacement standards that are often used instead of the withdrawn DIN method. In many purchasing and QA contexts, the replacement designation (and its edition) is what drives the current test procedure and reporting.
If your documentation mixes legacy DIN references with newer EN/ISO requirements, confirm the exact cited standard and edition before finalizing fixtures, specimen preparation, and reporting templates.
Get help configuring a ring tensile test setup
If you are equipping a lab for tube ring tensile testing and need to match fixture geometry and capacity to your tube sizes and compliance requirement, you can request a detailed quote for a UTM and ring-tensile fixture configuration.