Overview
ISO 6819:2023 - Steel wire rod for bridge cable wire specifies technical and quality requirements for steel wire rod intended for conversion into bridge cable wire used in parallel or semi-parallel wire cables for suspension bridges, stay bridges and similar structures. It covers designation, ordering data, production methods, dimensional and chemical requirements, delivery condition, inspection and testing protocols. The document cross‑references related ISO test methods and wire-rod series requirements.
Key topics and technical requirements
- Designation: Grades use a format like 82DB-3, where the number indicates midpoint carbon content (e.g., 82 = 0.80–0.85 % C), D = for wire drawing, B = bridge wire, and final digit = steel grade serial number.
- Dimensions & tolerances: Nominal rod diameters 11 mm to 16 mm; tolerances and out‑of‑roundness follow ISO 16124:2015 (T2) unless otherwise agreed.
- Chemical composition: Defined grade families from ~0.80 % to 1.00 % carbon with specified ranges for Si, Mn and limits for P, S, Cr, Cu and N. Product analysis deviations are tightly limited (example guidance: C ±0.04 %, Si ±0.04 %, Mn ±0.06 %; P and S subject to small over‑limit allowances). Boron addition (0.0005–0.0040 %) is permitted by agreement.
- Mechanical properties & delivery: Wire rod may be supplied hot‑rolled or heat‑treated; guaranteed mechanical properties can be agreed at order (informative guidance in Annex A). Patenting or special heat treatment may be required to meet property/microstructure objectives.
- Surface/internal quality: No detrimental internal or surface discontinuities; specific surface discontinuity limits (0.10 mm radial depth and 0.15 mm actual length) apply unless otherwise agreed.
- Microstructure & defects: Decarburization controlled to Class B (ISO 16120‑4); non‑metallic inclusions and core segregation assessed per referenced ISO methods; optional limits on resolvable pearlite (≤15 % for some grades, ≤10 % for others) and restrictions on martensite/bainite depending on alloying.
- Production & inspection: Steelmaking by BOF or EAF with ladle refining (supplier discretion unless specified). Inspection and test methods reference ISO standards such as ISO 16120‑1/4, ISO 16124, ISO 16574, ISO 6892‑1, ISO 4967 and others.
Applications and users
ISO 6819:2023 is used by:
- Steelmakers and wire‑rod producers producing rod for bridge cables
- Cable manufacturers and wire‑drawing plants converting rod into prestressing/bridge wires
- Bridge designers, structural engineers and procurement/specification authors writing material requirements
- Inspection labs and conformity assessors performing chemical, mechanical and metallographic testing
Practical benefits include consistent material performance for long‑span bridge cables, clearer procurement specs, and harmonized test/inspection routines to reduce risk in critical structural applications.
Related standards
Keywords: ISO 6819:2023, steel wire rod, bridge cable wire, suspension bridges, stay bridges, wire rod dimensions, chemical composition, decarburization, non‑metallic inclusions, resolvable pearlite.