Overview
EN ISO 20753:2023 - Plastics - Test specimens (adopted by CEN) compiles the designations, dimensional requirements and preparation guidance for commonly used plastics test specimens. The standard covers specimens intended for processing by injection moulding, compression moulding or prepared by machining from sheets and shaped articles. Its purpose is to harmonize specimen types and dimensions so laboratories and manufacturers can obtain comparable mechanical and physical data across tests.
Key topics and requirements
- Specified specimen types - The standard defines the following core specimen forms:
- A: Tensile specimen (multipurpose or reduced-scale)
- B: Bar specimen
- C: Small tensile specimen
- D: Square plate specimen
- F: Rectangular plate specimen
- Dimensional requirements - Detailed designations and dimensional symbols (for example l, b, r, h) are provided to ensure consistent geometry for tensile, bar and plate tests.
- Preparation methods - Requirements and references for specimen production by injection moulding, compression moulding, or machining (e.g., ISO 294 series, ISO 293, ISO 295, ISO 2818).
- Surface and marking - Specimens shall be free from visible flaws; moulded and machined specimens must be marked to identify moulding sides or asymmetry.
- Tolerances and harmonization - The 2023 edition harmonizes tolerances for radii, widths and lengths and clarifies tolerances for total length (important for grip spacing).
- Flexibility - The standard notes that omission of a specimen type does not exclude its use; additional commonly used specimen types can be added later.
Applications and users
EN ISO 20753:2023 is essential for anyone involved in the testing, specification or development of plastic materials:
- Materials testing laboratories - to prepare standardized specimens for tensile, flexural and other mechanical tests.
- Plastics manufacturers and moulder suppliers - to design moulds and production processes that produce compliant test specimens.
- R&D and quality control teams - to compare material performance reliably across batches and suppliers.
- Certification bodies and specifications authors - to reference harmonized specimen dimensions in test methods and regulatory documents.
Practical benefits include better comparability of test data, reduced variability from inconsistent specimen geometry, and clear guidance for specimen preparation workflows (injection/compression moulding or machining).
Related standards
Key normative references integrated with EN ISO 20753:2023 include:
- ISO 293, ISO 294‑1/2/3/5 (injection/compression moulding guidance)
- ISO 295 (thermosetting compression moulding)
- ISO 2818 (preparation by machining)
- ISO 10724‑1 (thermosetting powder moulding compounds)
Keywords: EN ISO 20753:2023, plastics test specimens, tensile specimen, injection moulding, compression moulding, test specimen dimensions, multipurpose test specimens, ISO 20753, CEN.