Overview
ISO 17832:2018 - Non-parallel steel wire and cords for tyre reinforcement specifies definitions and requirements for non-parallel steel filaments, strands and cords used inside pneumatic tyres. The standard covers classification, designation and ordering, dimensional and mechanical requirements, technological properties, coating/adhesion criteria, sampling and packing. It is intended to ensure consistent performance, interchangeability and traceability of steel cords used in tyre manufacturing.
Key Topics and Requirements
- Classification
- Tensile strength levels: NT, HT, ST, UT (normal → ultra tensile).
- Cord structures: single-strand, M+N type, layer, multi-strand.
- Cord types: HE (high-elongation), OC (open), CC (compact), WC (wavy), HI (high impact).
- Designation and ordering
- Standardized notation describing cord construction (e.g. 3 + 9 + 15 × 0,175 + 0,15), tensile class, cord type, lay length/direction and coating.
- Dimensions, mass and tolerances
- Requirements for cord diameter, linear density and permitted tolerances are specified.
- Recent edition tightened several tolerances (e.g., lay length tolerance narrowed from ±10% to ±5%).
- Mechanical properties
- Tests and acceptance criteria for breaking load, elongation at fracture, structural elongation and weld/splice strength.
- Technological properties
- Straightness, arc height, residual torsion, flare, steel cord elasticity and rubber penetration (including wavy cord designs to improve penetration).
- Tolerances for residual torsion refined for certain constructions.
- Coating and adhesion
- Brass coating mass fraction, thickness and composition requirements plus adhesion force criteria between steel cord and rubber.
- Sampling and packing
- Sampling schemes reference ISO 2859-1 and ISO 3951 series; packing and spool requirements specified to protect cord integrity during transport and storage.
Applications and Users
- Who uses ISO 17832:2018
- Tyre manufacturers and production engineers specifying reinforcement materials.
- Steel cord manufacturers and suppliers creating product datasheets and order confirmations.
- Quality/control laboratories performing mechanical and adhesion testing.
- Purchasing, R&D and regulatory teams ensuring material compliance and interchangeability.
- Practical value
- Ensures predictable tyre reinforcement performance (strength, fatigue resistance, adhesion).
- Simplifies procurement and supplier communication via standardized designation and testing.
- Reduces field failures by setting limits for welds/splices, coating quality and cord geometry.
Related Standards
- ISO 2859-1 (sampling by attributes)
- ISO 3951 series (sampling by variables)
- Prepared by ISO/TC 17 (Steel), SC 17 (Steel wire rod and wire products)
Keywords: ISO 17832:2018, non-parallel steel wire, steel cords, tyre reinforcement, cord tensile strength, brass coating, tyre manufacturing, cord designation.
