Overview
ISO 11951:2016 - "Cold-reduced tinmill products - Blackplate" defines requirements for single and double cold‑reduced blackplate supplied in coil form for the manufacture of electrolytic tinplate and electrolytic chromium / chromium‑oxide coated steel (ECCS) per ISO 11949 and ISO 11950. The standard covers dimensional ranges, manufacturing and finishing features, mechanical property requirements, inspection and testing, and packaging/marking rules for coils with nominal minimum rolling widths of 600 mm (500 mm by agreement).
Key topics and technical requirements
- Product scope and definitions: Distinguishes single cold‑reduced (final reduction, anneal, temper‑roll) and double cold‑reduced (second major reduction after annealing) blackplate.
- Thickness ranges:
- Single cold‑reduced: 0.150 mm to 0.600 mm, in 0.005 mm steps.
- Double cold‑reduced: 0.100 mm to 0.360 mm, in 0.005 mm steps.
- Coil form and edges: Applies to coils with trimmed or untrimmed edges; coil joint, orientation and labelling requirements specified.
- Manufacturing features: Requirements for annealing, surface finish, oiling and permissible imperfections.
- Mechanical properties and tests:
- Hardness (Rockwell) and tensile property requirements are specified; hardness tests reference ISO 6508-1, tensile tests reference ISO 6892-1.
- Flatness and shape tolerances (edge wave, longitudinal/transverse bow, centre fullness).
- Dimensional tolerances: Thickness, feather edge, coil width/length and edge camber tolerances defined.
- Quality assurance: Sampling, test methods, retests, and inspection documents (see ISO 10474) are required to ensure conformity.
- Normative and informative annexes: Include hardness and tensile requirement tables, steel type guidance, springback routine tests and Rockwell equivalent charts.
Practical applications and who uses this standard
- Steel producers / tinmill manufacturers: Use ISO 11951 to specify cold‑reduction, annealing and finishing processes to meet downstream tinplating and ECCS needs.
- Tinplate and ECCS manufacturers: Use it to verify incoming coil quality (mechanical properties, flatness, dimensions) before surface coating to ensure process compatibility and yield.
- Packaging converters and canmakers: Rely on the standard to ensure substrate properties meet forming, coating and corrosion‑protection requirements for food and general packaging.
- Procurement, quality and testing laboratories: Use ISO 11951 for purchase specifications, acceptance testing and inspection documentation to ensure traceability and compliance.
Related standards
- ISO 11949 - Electrolytic tinplate
- ISO 11950 - Electrolytic chromium / chromium‑oxide coated steel (ECCS)
- ISO 404 - General technical delivery requirements (steel)
- ISO 6508-1 - Rockwell hardness test
- ISO 6892-1 - Tensile testing at room temperature
- ISO 10474 - Inspection documents
Keywords: ISO 11951:2016, blackplate, cold‑reduced, tinmill products, electrolytic tinplate, ECCS, coil specifications, thickness tolerances, hardness test, tensile test, flatness.