ISO 16120-2:2017

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

• 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).

• 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.

• Internal soundness & surface quality

  • Wire rod shall be free from detrimental internal/surface discontinuities (shrink holes, cracks, folds, scabs, burrs).

• 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).

• 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.

• 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).

• 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.