ISO 8495 is an international test method for the ring-expanding test on metallic tubes. A short ring cut from the tube is expanded with a conical mandrel until fracture to help reveal defects and evaluate the tube’s ability to undergo plastic deformation.
If you are unsure whether ring-expanding is the right ductility or defect-reveal check for your tube size and product requirement, talk with our team about your application and what you need to report.
ISO 8495: Metallic materials — Tube — Ring-expanding test
ISO 8495 describes how to perform a ring-expanding test on metallic tubes using a conical mandrel. The method is commonly used as a fast, practical ductility and integrity check for tube products where cracking, splitting, or other discontinuities must be detected under expansion.
The standard is written around expanding a ring-shaped test piece until fracture and evaluating the result (including the expansion achieved at fracture where required by the purchase specification).
Quick Definition
What it is: A mechanical-technological tube test where a tube ring is expanded with a conical mandrel until it fractures.
What it indicates: Surface and through-wall discontinuities that open during expansion, plus general formability/ductility under circumferential strain.
What it is not: A substitute for a full tensile test or a fracture toughness test; it is a product-focused expansion check.
What This Standard Covers
ISO 8495 specifies a ring-expanding method for tubes where the test piece is expanded using a conical mandrel until fracture occurs. The standard is used to reveal defects on the tube surfaces and within the tube wall, and it may also be used to assess the ability of tubes to undergo plastic deformation.
Dimensional applicability (per the standard abstract): Tubes with outside diameter from 18 mm up to and including 150 mm, with wall thickness from 2 mm up to and including 16 mm.
Why This Standard Matters in Testing
Ring-expanding is often selected when tube purchasers or internal quality plans need evidence that the tube can tolerate forming or in-service deformation without splitting. Because the ring is expanded until fracture, the test can be sensitive to brittle behavior, seam/weld quality concerns, and defects that may not be obvious under visual inspection alone.
For labs and production QA/QC teams, ISO 8495 is also a practical way to standardize fixturing and reporting for an expansion-to-fracture check so that results can be compared across lots, suppliers, or processes.
Common Materials, Product Types, or Applications Covered
This method is used for metallic tube products where expansion performance is relevant. It is often applied in incoming inspection, process qualification, or routine quality control for tube manufacturing and tube forming supply chains.
Common product focus: Round metallic tubes where ring samples can be cut and expanded using a conical mandrel, within the dimensional ranges cited for the method.
Common Test or Verification Workflow
Most ISO 8495 workflows follow a straightforward sequence: select and identify the tube, cut a ring test piece, measure relevant starting dimensions, expand the ring with a conical mandrel until fracture, and record the observed result and any required expansion value(s).
Common outputs: Pass/fail against an acceptance criterion set by the product specification, plus documented observations of cracking/fracture behavior and the achieved expansion where applicable.
Equipment Commonly Used for This Standard
ISO 8495 is equipment-oriented in the sense that it requires controlled expansion of a ring test piece using a conical mandrel. In practice, the equipment package is typically built around a force-applying frame and a dedicated mandrel/fixture set sized to the tube being tested.
Common equipment families: A mechanical or hydraulic press (or a universal testing machine used in compression), ring-expanding tooling with a conical mandrel, and basic dimensional metrology for tube OD/wall and post-test measurements as required.
If you are matching tooling to multiple tube sizes or setting up a repeatable lab workflow for expansion-to-fracture testing, you can request a detailed quote for a configured system (frame capacity, fixture design approach, and sample handling needs).
How to Read This Designation or Revision
Designation format: ISO 8495:2013 identifies the ISO standard number (8495) and the edition year (2013).
Why the year matters: Purchase orders, customer requirements, and lab procedures may cite a specific edition year. When quoting equipment or writing work instructions, align the tooling concept and reporting expectations to the exact cited edition and any additional product specification requirements.
Status note: ISO standards are periodically reviewed; always confirm the cited edition in your customer documentation before finalizing a test plan.
Related Standards, Methods, or Frameworks
Tube formability and integrity checks are often specified as a set. Depending on what deformation mode your requirement is trying to simulate, you may also see other ISO tube tests referenced alongside ring-expanding.
- ISO 8492: Tube flattening test (plastic deformation under flattening).
- ISO 8493: Tube drift-expanding test (expansion using a drift/mandrel approach for certain tube conditions).
Discuss your ISO 8495 testing setup
For ring-expanding tests, the right setup usually comes down to tube size range, how you want to measure/record expansion, and how you want the fracture outcome documented. If you want help selecting a practical fixture and frame configuration for your lab, contact our team with your tube OD/wall range and the requirement you need to meet.