What Is Tensile?
The tensile test is a test in which a plastic (ISO 527) or rubber (ISO 37) sample prepared in standard geometry is pulled at a constant speed; It is the test where tensile strength, elongation at break and tensile modulus are determined.
Purpose of Tensile
The purpose is to verify that the strength and ductility properties of the material meet the specification limits.
Which Products Is Tensile Applied To?
- Injection and extrusion plastic parts
- Films and sheets
- Elastomer and gasket materials
- Takviyeli kompozitler
In Which Sectors Is Tensile Used?
Standards Related to Tensile
- ISO 527-1
- ISO 527-2
- ASTM D638
- ISO 37 (rubber)
- ISO 6892 (separate standard for metal)
Tensile Conditions
- Specimen
- Type defined in the standard (e.g. ISO 527-2 Type 1A/1B, ISO 37 ring or double spade)
- Tensile speed
- Defined in the standard; separate low speed is used for module measurement
- Conditioning
- Duration defined in the standard at 23 °C ± 2 °C and 50 ± 10% relative humidity
- Quantities measured
- Tensile strength, yield strength, elongation at break, tensile modulus
Equipment for Tensile
- Caliber universal tester
- Extensometer (contact or optical)
- Sample cutting die or processing bench
- Air-conditioned conditioning room
Sample Requirements for Tensile
- Sample dimensions and thickness must comply with the standard
- Sample edges must be free of notches
- Conditioning must be completed in the environment defined in the standard
- The number of samples is usually at least five
Duration of Tensile
Typically 3–5 days including conditioning.
Tensile Procedure
- 1Samples are prepared and conditioned according to the standard.
- 2Thickness and width are measured.
- 3The extensometer is fitted.
- 4Pulling is applied at a defined speed.
- 5The load–elongation curve is recorded.
- 6Strength, elongation and modulus are calculated.
Tensile Acceptance Criteria
Acceptance criteria are the minimum strength and elongation values given in the material standard or specification.
Evaluation of Results
Pulling speed and conditioning change the result significantly; plastics are viscoelastic. Module measurement is done separately and at a lower speed; the module value read from the same experiment may not comply with the standard.
Tensile Report
- Applied standard and sample type
- Conditioning conditions
- Tensile speed
- Measured strength, elongation and modulus
- Rupture shape and location
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Material product standards
- Automotive and electrical product specifications
Plastics Testing — What Does This Testing Field Cover?
The section below describes the field that the Tensile test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Plastics testing determines the mechanical, thermal and burning behaviour of a polymer material. Unlike metals, plastics are VISCOELASTIC: their behaviour depends on loading rate, temperature and moisture. The same material therefore gives different results under different conditions, and the test conditions are an inseparable part of the result.
The practical consequence of viscoelasticity is this: a plastic part continues to deform over time under a constant load (creep) and the stress it carries at constant deformation falls over time (stress relaxation). A screwed joint loosens, a clamp loses its clamping force, a shelf sags over time. A short-term tensile test does not show this behaviour; a long-term test or an accelerated model is needed.
Thermal behaviour is the second main axis. Melt flow rate indicates the processability of the material and lot-to-lot consistency; heat deflection temperature and the Vicat softening point give a rough limit for service temperature. Thermal analysis (DSC, TGA, DMA) reveals the identity of the material: glass transition temperature, melting behaviour, crystallinity, filler content and decomposition temperature.
Burning behaviour is the third axis and ties directly into product standards. The UL 94 class and the limiting oxygen index are written into the material data sheet; a particular class is required for the housing of an electrical appliance, while a different classification system applies to a construction product.
Ageing is the most frequently skipped part of the field. Plastics degrade under UV, heat, moisture and oxygen: colour changes, the surface cracks, impact strength falls. For a part intended for outdoor use, what matters is not its values on day one but its values after ageing. Xenon arc and fluorescent UV equipment accelerate this degradation and allow comparison.
The output of this family is usually written into the material data sheet, and product standards refer to that sheet. But there can be a difference between the data sheet value and the behaviour of the actual part: orientation formed during moulding, weld lines and internal stresses make the part behave differently from the specimen.
The use of recycled content has added a new question to the field. Recycled resin varies from lot to lot; mechanical properties, colour and burning behaviour can shift between batches. For a manufacturer using recycled material, incoming material control is therefore not a choice but a necessity.
Method groups in this field
Mechanical
Tension, compression, bending, Charpy and Izod impact, hardness (Shore), creep and environmental stress cracking.
Thermal
Melt flow index (MFI), heat deflection temperature (HDT), Vicat softening temperature, linear thermal expansion.
Thermal analysis
Transition temperatures and crystallinity by DSC, composition and decomposition by TGA, dynamic mechanical behaviour by DMA.
Burning
UL 94 classification, limiting oxygen index (LOI), glow wire and needle flame tests.
Ageing
Accelerated ageing by xenon arc and fluorescent UV, hot air ageing, humidity and condensation.
Physical
Density, water absorption, ash content, gas and water vapour permeability of films and sheets.
Commonly confused in this field
- A plastics result without a stated test rate and temperature cannot be interpreted; viscoelastic behaviour depends on these parameters.
- A specimen result does not transfer directly to the actual part; moulding orientation and weld lines are decisive.
- HDT and Vicat values are NOT service temperatures; they are a rough indication of an upper limit and do not apply under load.
- The UL 94 class depends on thickness; a different wall thickness requires re-verification.
- For moisture-absorbing polymers (such as polyamide), results are misleading unless conditioning is carried out.
- ASTM D638 and ISO 527 results are not directly equivalent; the specimen geometries and rate definitions differ.
Which decisions these results support
- Material selection and supplier approval
- Meeting the flammability and thermal requirements of the product standard
- Verifying the use of recycled content and lot control
- Moulding process control and lot consistency
- Demonstrating ageing resistance for outdoor use
Related Tests
Frequently Asked Questions About Tensile
According to which standard is Tensile made?
Tensile is executed in scope ISO 527-1, ISO 527-2, ASTM D638, ISO 37 (rubber) and ISO 6892 (separate standard for metal). The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Tensile apply to?
Mainly applied to Injection and extrusion plastic parts, Films and sheets, Elastomer and gasket materials and Takviyeli kompozitler. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Tensile done?
The determining parameters are: Specimen — Type defined in the standard (e.g. ISO 527-2 Type 1A/1B, ISO 37 ring or double spade), Tensile speed — Defined in the standard; separate low speed is used for module measurement and Conditioning — Duration defined in the standard at 23 °C ± 2 °C and 50 ± 10% relative humidity. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Tensile?
Sample dimensions and thickness must comply with the standard, Sample edges must be free of notches and Conditioning must be completed in the environment defined in the standard. The number of samples is determined according to the product standard and the scope to be reported.
How long does Tensile take?
Typically 3–5 days including conditioning. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Tensile result called "appropriate"?
Acceptance criteria are the minimum strength and elongation values given in the material standard or specification.