Overview
ISO 16120-2:2017 specifies specific requirements for general purpose non‑alloy steel wire rod intended for conversion to wire by drawing and/or cold rolling. It supplements the general provisions in ISO 16120‑1 and defines grade designations (C##D), ordering options (by chemical composition or by tensile strength), and acceptance criteria that producers, buyers and testing laboratories use to ensure consistent quality of wire‑rod feedstock.
Keywords: ISO 16120-2, non-alloy steel wire rod, general purpose wire rod, wire drawing, cold rolling, steel grades.
Key topics and technical requirements
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Scope and designation
- Applies to general purpose steel wire rod for drawing and/or cold rolling.
- Grade format: C##D (C = non‑alloy steel, ## = indicative average carbon content, D = wire‑drawing).
- Option to specify mid‑point UTS as a suffix (e.g. C##D – 1020).
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Chemical composition
- Heat‑analysis limits are defined per grade (C4D through C92D) for C, Si, Mn, P, S, Cu, Al and other elements.
- Product analysis permissible deviations (examples): Carbon ±0.02 to ±0.04 (depending on grade); Si ±0.04; Mn ±0.06; P and S +0.005.
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Internal soundness & surface quality
- Wire rod shall be free from detrimental internal/surface discontinuities (shrink holes, cracks, folds, scabs, burrs).
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Surface discontinuity limits
- For round wire rod: maximum radial depth and maximum actual length limits (e.g. for nominal diameter 5 ≤ d ≤ 12 mm: radial depth ≤ 0.20 mm, actual length ≤ 0.25 mm; for d > 12 mm: radial depth ≤ 0.25 mm, actual length ≤ 0.30 mm).
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Core segregation
- For grades C60D and higher, not more than 20% of inspected test pieces may be Class 4 and none Class 5 (per ISO 16120‑1 Annex A), unless otherwise agreed.
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Tensile strength
- Two permissible variation options (Option A and Option B) specify batch mean and coil‑to‑coil variation ranges (e.g. Option A: ±40 to ±60 MPa depending on grade).
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Scale characteristics & mechanical damage
- Scale quantity/descalability and permissible abrasive/mechanical damage are subject to agreement between supplier and purchaser.
Applications
- Feedstock specification for manufacturers of cold‑drawn wire, nails, springs, fasteners, welded mesh, and other drawn/cold‑worked wire products.
- Quality control and incoming inspection criteria for wire mills, drawing shops and procurement teams.
- Basis for contractual purchase terms and supplier quality agreements.
Who should use this standard
- Steel producers and rod mills, wire manufacturers, procurement engineers, Q‑A/Q‑C laboratories, product designers and standards committees dealing with wire‑rod supply and performance.
Related standards
- ISO 16120‑1 (General requirements for non‑alloy steel wire rod)
- ISO 4948‑2 (Classification of unalloyed and alloy steels)
- Annex A of ISO 16120‑2 lists comparable national/regional steel grade designations (e.g. JIS, GB/T) where applicable.