ISO standardsISO

Standards developed by ASTM International, a US-based standards organisation whose test methods are used worldwide, particularly in aerospace and composites, for example ASTM D3039 for tensile testing of polymer matrix composites. Datasheets often quote both ASTM and ISO methods; results are broadly comparable but not always directly interchangeable.

European Standards produced by the European standardisation bodies and adopted identically by national standards institutes, appearing in the UK as BS EN standards. Harmonised ENs under the Construction Products Regulation define how construction products, including roofing membranes and insulation, are tested, classified and CE marked.

A mechanical test in which a specimen is pulled along its axis until it breaks, measuring properties such as tensile strength, tensile modulus and elongation at break. For plastics and composites it is commonly performed to methods in the ISO 527 series or ASTM D638 and D3039. It is the baseline test for characterising resins, laminates and reinforcement materials.

An independent organisation, usually accredited by a national accreditation service, that assesses products, management systems or personnel against standards and issues certificates of conformity. Third-party certification gives specifiers confidence beyond a manufacturer's own declaration of performance.