ISO 527-1:2019

Overview

ISO 527-1:2019 - Plastics - Determination of tensile properties - Part 1: General principles defines the general principles and test framework for measuring tensile behaviour of plastics and plastic composites. This ISO standard sets out how to determine tensile strength, tensile modulus, and other stress–strain characteristics under defined conditions. It provides the foundational requirements used across the ISO 527 series; specific specimen types and detailed methods are given in subsequent parts.

Key topics and technical requirements

• Scope and applicability: Suitable for rigid and semi‑rigid thermoplastics and thermosets, filled/reinforced compounds, sheets, films, fibre‑reinforced composites (unidirectional and woven), prepregs and thermotropic liquid crystal polymers. Not normally suitable for rigid cellular materials (use ISO 1926) or sandwich structures with cellular cores.
• Principle and methods: Defines how tensile tests are performed to obtain engineering stress vs. strain curves and key parameters such as stress at yield (σy), strength (σm), stress at break (σb) and stress at a specified strain (σx).
• Apparatus requirements: Specifies testing machine capabilities, grips, force measurement (calibration per ISO 7500‑1), extensometer/strain measurement accuracy (see ISO 9513), and devices for dimensional measurement.
• Specimen preparation and geometry: Covers specimen shapes, gauge marks, thickness/width measurement, anisotropy considerations and conditioning (per ISO 291).
• Test procedure and data handling: Guidance on test atmosphere, gripping, prestress, setting of extensometers, test speeds, data recording, calculation of stress/strain, tensile modulus (chord and regression slopes), Poisson’s ratio, statistical treatment and reporting.
• Annexes: Informative annexes address determination of strain at yield and extensometer accuracy for Poisson’s ratio; a normative annex covers calibration requirements for tensile modulus determination.

Applications and users

ISO 527-1:2019 is used by:

• Materials engineers and R&D teams for characterizing mechanical behaviour of plastics and composites.
• Quality control laboratories for lot acceptance and supplier verification.
• Product designers performing material selection and comparative testing.
• Test labs preparing compliance reports and specifications that reference tensile strength, modulus, or elongation. Practical uses include performance benchmarking, failure analysis, specification writing, and correlating material data with design requirements.

Related standards

• ISO 527 (other parts) - specimen-specific test methods
• ISO 1926 - rigid cellular plastics
• ISO 291 - conditioning and testing atmospheres
• ISO 7500‑1, ISO 9513 - calibration of test machines and extensometers
• ISO 16012, ISO 2602, ISO 23529 - dimensional measurement, statistics, and specimen conditioning

Keywords: ISO 527-1:2019, tensile properties, plastics tensile testing, tensile strength, tensile modulus, extensometer, test specimen, stress-strain curve, plastics standards.