Overview
ISO 16172:2018 - Steel sheet, metallic‑coated by the continuous hot‑dip process for corrugated steel pipe - defines minimum requirements for metallic‑coated steel sheet supplied in coils, flat cut lengths and corrugated cut lengths for manufacture of corrugated steel pipe. The product is intended for storm sewers, culverts, drains and similar civil infrastructure. The standard covers four hot‑dip coating systems: zinc (Zn), zinc‑5% aluminium‑mischmetal (Zn‑5Al‑MM), 55% aluminium‑zinc (55Al‑Zn) and aluminium‑silicon (Al‑Si).
Key topics and technical requirements
- Materials & coatings: Specifies four metallic coatings and their required total coating mass (both sides), for example:
- Zn - single‑spot min. 610 g/m², triple‑spot average min. 550 g/m²
- Zn‑5Al‑MM - single‑spot min. 640 g/m², triple‑spot average min. 550 g/m²
- 55Al‑Zn - single‑spot min. 210 g/m², triple‑spot average min. 180 g/m²
- Al‑Si - single‑spot min. 305 g/m², triple‑spot average min. 275 g/m²
- Mechanical properties (base metal prior to fabrication): tensile strength min. 310 MPa, yield strength min. 230 MPa, elongation in 50 mm min. 20%.
- Dimensions and tolerances: Defines coated‑sheet thicknesses (e.g., specified 1.0 to 4.3 mm with minimums), flatness, length tolerances, corrugation geometry (pitch, depth) and covering/lip dimensions for corrugated sheet.
- Coating performance: Requires coating adherence such that no peeling or flaking occurs during corrugating/forming; includes single‑spot and triple‑spot coating tests and gravimetric coating mass determination (see ISO 1460).
- Testing & inspection: Refers to tensile testing (ISO 6892‑1), coating mass methods, sampling (one tensile test per lot ≤ 50 t), workmanship, resubmission, inspection, certification and marking requirements.
- Surface treatment: Chemical treatments to reduce wet‑storage stain are covered; treated material must be handled/dried if received wet.
Applications and users
- Primary uses: Corrugated steel pipes for storm sewers, culverts, drainage systems and similar civil engineering works.
- Who uses this standard:
- Steel sheet manufacturers and hot‑dip coating producers
- Fabricators of corrugated pipe and culvert panels
- Specifiers and civil engineers writing procurement documents
- Procurement officers, inspectors and testing laboratories
- Practical guidance: Select the coating type and mass based on expected environment (corrosion exposure, service life) and downstream forming requirements; verify coating adherence and mechanical properties before corrugating.
Related standards
- ISO 1460 - Gravimetric determination of coating mass (hot‑dip galvanized)
- ISO 6892‑1 - Tensile testing at room temperature
- ISO 16163 - Dimensional and shape tolerances for continuously hot‑dipped coated steel sheet
ISO 16172:2018 provides a concise framework for quality, dimensional control and coating performance of metallic‑coated steel sheet used to produce durable corrugated steel pipe for infrastructure projects.