ISO 20058:2017

Overview

ISO 20058:2017 - General purpose rubber thread - Specification defines uniform physical and mechanical requirements for general-purpose rubber threads. The standard sets dimensional tolerances, performance limits and labelling/packaging expectations to ensure consistent quality and interchangeability. It explicitly excludes rubber threads intended for food contact, furniture, high heat resistance and high ozone resistance applications.

Key Topics and Requirements

• Scope & exclusions: Applies to general-purpose rubber thread only; excludes specialized uses such as food contact and high-heat/ozone resistant threads.
• Classification: Threads are classified by cross-section into Type 1 (round), Type 2 (square) and Type 3 (rectangular), and further subdivided into Class 1, 2, 3 by mechanical properties.
• Dimensional tolerances: Conventional count (size) is agreed between purchaser and manufacturer. Diameter or cross-sectional length tolerance for round/square/rectangular threads is ±3% unless otherwise specified.
• Metric yield & density: Metric yield must be within ±6% of declared value. Density categories (when agreed and tested) are:
  • Low density: < 1.10 g/cm³
  • Medium density: 1.10–1.20 g/cm³
  • High density: > 1.20 g/cm³
• Physical & mechanical properties (tested per ISO 2321:2017):
  • Modulus at 300%, tensile strength, elongation at break and tension set have specified limits that vary by Class 1–3.
  • Requirements include minimum retained strength and elongation after accelerated ageing.
• Schwartz value (informative): Recommended measurement at 300% elongation; preferred value 1.3 MPa ± 25% when required.
• Packaging & marking: Material shall be packed for safe transport/storage. Packages must show material, conventional count, colour, number in ribbon, class, weight (kg), and date of manufacture or lot number.

Applications and Who Uses It

ISO 20058:2017 is aimed at organizations involved in the production, procurement and testing of general-purpose rubber threads:

• Rubber thread manufacturers for product specification and quality control
• Textile and garment manufacturers using elastic threads in clothing, bands and trims
• Supply chain/procurement teams specifying material acceptance criteria
• Quality assurance and testing laboratories performing mechanical and ageing tests
• Standards bodies and compliance officers ensuring consistent labelling and packaging

The standard helps ensure reliable performance (modulus, tensile strength, elongation and tension set) for everyday elastic applications while providing clear test and marking expectations.

Related Standards

• ISO 2321:2017 - Rubber threads - Methods of test (referenced throughout ISO 20058:2017 for test methods and clauses)

Keywords: ISO 20058:2017, rubber thread specification, general purpose rubber thread, modulus, tensile strength, elongation, tension set, Schwartz value, ISO 2321.