ISO 20457-2018 PDF

Full title and description

ISO 20457:2018 — Plastics moulded parts — Tolerances and acceptance conditions. This International Standard gives recommended manufacturing tolerances and acceptance conditions for non‑porous moulded plastic parts made by common moulding processes and provides a basis for specifying dimensional and geometrical tolerances using ISO‑GPS tools.

Abstract

This document specifies possible manufacturing tolerances for plastic moulded parts, covering integral features with general tolerances and surface profile tolerances within a specified datum system. It permits additional, function‑driven specifications using ISO‑GPS tools for dimensional and geometrical tolerancing. The scope covers injection moulding, injection‑compression, transfer, compression and rotational moulding of non‑porous parts made from thermoplastics, thermoplastic elastomers and thermosets. Surface defects such as sink marks, undesired flow structures, roughness and joint lines are not addressed. The standard is not intended to override product‑specific tolerance requirements.

General information

• Status: Published (Edition 1). Last reviewed and confirmed by ISO in 2024; listed for revision (stage 90.92).
• Publication date: September 2018 (first published 2018‑09 / effective late August–September 2018).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 83.140.01 (Products in elastomers or plastics in general).
• Edition / version: Edition 1 (2018).
• Number of pages: 28 pages (official ISO publication length).

Scope

ISO 20457:2018 specifies recommended manufacturing tolerances and acceptance conditions for non‑porous plastics moulded parts and defines how to apply general dimensional tolerances and surface profile tolerances within an agreed datum system. It applies to parts produced by injection moulding, injection‑compression moulding, transfer moulding, compression moulding and rotational moulding using thermoplastics, thermoplastic elastomers and thermosets; it may be applied to other processes if agreed contractually. The standard excludes guidance on surface defects (sink marks, flow marks, roughness, weld/join lines) and does not supersede product‑specific tolerance requirements found in other standards.

Key topics and requirements

• Definition of general manufacturing tolerances for integral features of moulded plastic parts.
• Specification of surface profile tolerances within a declared datum system.
• Use of ISO‑GPS (Geometrical Product Specifications) tools to add functional dimensional and geometrical tolerancing where required.
• Application to injection, injection‑compression, transfer, compression and rotational moulding of non‑porous thermoplastics, thermoplastic elastomers and thermosets.
• Explicit exclusion of surface imperfections (sink marks, undesirable flow structures, roughness, joint lines) from tolerance acceptance rules.
• Guidance intended to be compatible with, and not to replace, product‑specific tolerance requirements in other standards.

Typical use and users

Design engineers, tooling and mould designers, production managers, quality/inspection engineers, metrology laboratories, purchasing/procurement teams, and product standards writers use ISO 20457:2018 as a reference when specifying tolerances for plastic moulded components and when developing inspection/acceptance criteria in procurement contracts or product specifications.

Related standards

ISO 20457 is intended to be used alongside other ISO GPS and plastics standards such as ISO 10135 (drawings of moulded parts), ISO 14405‑1 (linear dimension tolerances), ISO 2577 (shrinkage of thermosetting moulding materials), ISO 291 (conditioning for testing plastics), ISO 8015 (fundamentals of GPS), and ISO 286 (basic tolerances). National/adopted versions and earlier national standards (for example DIN 16742) are also related references.

Keywords

Plastics moulded parts, tolerances, acceptance conditions, injection moulding, injection‑compression, transfer moulding, compression moulding, rotational moulding, ISO‑GPS, dimensional tolerancing, geometrical tolerancing, metrology.

FAQ

Q: What is this standard?

A: ISO 20457:2018 is an International Standard titled "Plastics moulded parts — Tolerances and acceptance conditions" that provides recommended manufacturing tolerances and acceptance criteria for non‑porous moulded plastic parts.

Q: What does it cover?

A: It covers recommended dimensional and surface‑profile tolerances for integral features of moulded plastic parts, application of ISO‑GPS tools for additional functional tolerancing, and acceptance conditions for parts produced by common moulding processes. It specifically excludes surface defect criteria (e.g., sink marks, flow marks, roughness, joint lines).

Q: Who typically uses it?

A: Designers, mould/tooling engineers, manufacturers, quality and inspection personnel, procurement specialists and standards writers who need a standardized basis for specifying and inspecting tolerances on plastic moulded components.

Q: Is it current or superseded?

A: As published in September 2018 (Edition 1), ISO 20457:2018 remains the current edition; ISO records show it was reviewed and confirmed in 2024. The standard is listed for revision and a draft revision (ISO/DIS 20457, edition 2) has been developed, so a new edition is under work and may replace the 2018 edition when published.

Q: Is it part of a series?

A: It is part of the body of ISO standards addressing plastics and the ISO GPS (Geometrical Product Specifications) system and should be used in conjunction with related standards (for example ISO 14405, ISO 10135, ISO 8015 and others referenced in product and testing standards). The technical oversight is by ISO/TC 61 (Plastics), subcommittee SC 11.

Q: What are the key keywords?

A: Plastics moulded parts; tolerances; acceptance conditions; ISO‑GPS; injection moulding; dimensional tolerancing; geometrical tolerancing; metrology; thermoplastics; thermosets.