Overview
EN ISO 16120-4:2017 - Non-alloy steel wire rod for conversion to wire, Part 4 - specifies specific requirements for wire rod for special applications. Published by CEN and identical to ISO 16120-4:2017, this part of the ISO 16120 series applies to non‑alloy steel wire rod with improved characteristics intended for drawing and/or cold rolling. It is the third edition (2017) and is intended for use together with ISO 16120‑1 (general requirements).
Key topics and technical requirements
EN ISO 16120-4:2017 addresses the quality and properties needed for wire rod destined for demanding or specialised downstream processes. Major technical topics include:
- Designation and ordering - grade format (e.g. C##D2) and option to specify tensile mid‑point in the designation (for example C##D2 – 1020).
- Chemical composition - required heat analysis ranges and permissible deviations for product analysis; limits for common elements relevant to drawing performance.
- Mechanical properties - tensile strength requirements and permissible variations (UTS mid‑point concept used for ordering).
- Internal soundness and surface quality - criteria to control internal defects and surface discontinuities that affect drawability.
- Decarburization - definitions and maximum permissible depths for complete or partial decarburization.
- Non‑metallic inclusions and core segregation - acceptance criteria and test methods to minimise drawing breaks and surface defects.
- Scale characteristics and mechanical damage - acceptable scale and handling damage limits that influence cold working.
- Microstructure - requirements for resolvable pearlite and a newly added cementite‑network requirement to control fracture and drawing behaviour.
- Normative references - links to related test methods and classifications (e.g. ISO 16120‑1, ISO 16120‑2, ISO 4967, ISO 4948‑2).
Practical applications
This standard is used to ensure uniform quality of wire rod for special applications where higher drawability, consistent mechanical performance and low defect rates are essential. Typical applications include:
- High‑strength drawn wire, music wire, spring wire and precision wire products
- Wire used for cold‑formed components, fine multi‑strand cables and speciality fasteners
- Any downstream process requiring tight control of chemistry, tensile properties, decarburization and microstructure
Who should use this standard
- Steel mills and wire‑rod producers specifying and producing non‑alloy wire rod
- Wire manufacturers and cold‑forming shops requiring reliable feedstock
- Quality assurance and purchasing teams specifying material acceptance criteria
- Engineers and product designers selecting wire grades for special applications
- Certification bodies and test laboratories performing compliance checks
Related standards
- ISO 16120‑1: General requirements for non‑alloy steel wire rod
- ISO 16120‑2: Specific requirements for general‑purpose wire rod
- ISO 4967: Method for non‑metallic inclusions
- ISO 4948‑2: Steel classification
Keywords: EN ISO 16120-4:2017, non‑alloy steel wire rod, wire rod for special applications, wire drawing, cold rolling, chemical composition, tensile strength, decarburization, non‑metallic inclusions.
