ISO 527-2 is a critical international standard used to determine the tensile properties of rigid and semi-rigid plastics. It is extensively used in Europe and Asia and is often compared to ASTM D638, although both standards differ in terms of specimen geometry, testing speeds, and data interpretation. At Fitco, we specialize in helping laboratories and manufacturers comply with ISO 527-2 by offering state-of-the-art tensile testing solutions from Testometric, a global leader in material testing equipment.
What Is ISO 527-2?
ISO 527-2 outlines procedures to measure mechanical properties such as tensile strength, modulus of elasticity, elongation at break, and Poisson’s ratio. These values are essential for material comparison, quality assurance, and R&D.
Key Measurements:
- Tensile Strength – Maximum stress before break or yield
- Tensile Modulus – Stiffness of the material
- Elongation at Break – Ductility and stretch capacity
- Poisson’s Ratio – Lateral strain to axial strain ratio
Recommended Testometric Configuration for ISO 527-2
Fitco recommends the Testometric XFS Series for ISO 527-2 compliance. These high-performance twin-column testing machines are designed for versatile plastics testing across multiple load ranges.
Ideal Configuration:
- Testometric XFS 5kN / 10kN / 50kN (based on sample strength)
- Testometric Pneumatic Grips with serrated jaw faces (for rigid and reinforced plastics)
- Testometric Manual Wedge Grips (for high-force applications above 10kN)
- Video Extensometer (Non-contact) (Class 1 ISO 9513 compliant)
- WinTest Analysis Software for programmable pre-loads, modulus regression, and stress-strain graphing
These components offer precision, repeatability, and full traceability, ensuring your lab meets both ISO and internal QA standards.
Specimen Types and Dimensions
ISO 527-2 defines several specimen geometries:
- Type 1A – Preferred for injection molded samples
- Type 1B – For machined test bars from extruded or molded sheets
Preferred Gauge Length: 75 mm (2012 update).
Legacy and QC workflows may still use 50 mm, which is acceptable.
Sub-sized specimens (Types 1BA, 1BB, 5A, 5B) can be used when sample material is limited, but they reduce accuracy for modulus and elongation due to shorter gauge lengths.
Gripping and Alignment Recommendations
Improper gripping can skew results and cause premature failure. Testometric’s Heavy-duty dual cylinder pneumatic side-action grips maintain a constant clamping force, ensuring specimens remain secure even as thickness varies during testing.
Tips for Alignment:
- Use jaws that match specimen width
- Implement mechanical alignment fixtures to maintain repeatable centering
- Preload specimens to remove slack and compressive effects before starting strain measurement
Extensometer Options for Accurate Modulus and Strain
For modulus testing (between 0.05% and 0.25% strain), a Class 1 extensometer is required:
- Testometric Video Extensometer – Ideal for necking or fragile samples
- Biaxial and Transverse Extensometers – For Poisson’s ratio and advanced elastic behavior analysis
To measure strain after yield accurately (especially for ductile materials), ISO 527-2 recommends Method B, which uses extensometer readings until yield, then crosshead displacement for nominal strain post-yield.
Data Reporting & ISO 527-2 Calculations
- Modulus: Slope between 0.05% and 0.25% strain (chord method)
- Tensile Strength: First local maximum (updated in 2012)
- Nominal Strain: Post-yield elongation via crosshead movement
All results must be accompanied by stress (N/mm² or MPa), which requires accurate cross-sectional area measurement per ISO 16012.
Automation & High-Throughput Testing
For QC labs or production settings, Testometric systems can be enhanced with:
- Non-Contact Video Extensometry – For delicate or highly extensible materials
Why Choose Fitco + Testometric for ISO 527-2?
- Decades of experience in plastics testing
- In-house support and application engineering in India
- Pre-configured ISO 527-2 methods available in WinTest software
- Installation, training, and after-sales service by certified Fitco engineers
Get Started with ISO 527-2 Compliance Today Whether you’re setting up a new lab or upgrading an existing line, Fitco’s experts can help you specify the right Testometric system to meet ISO 527-2 requirements with precision and reliability.