Overview
ISO 11950:2026 is an international standard developed by ISO that specifies the requirements for single and double cold-reduced electrolytic chromium/chromium oxide-coated steel (ECCS), also commonly known as tinmill steel or "tin-free steel". This standard covers ECCS products in the form of sheets and coils, intended primarily for packaging and industrial applications. The content addresses cold-reduced, non-alloy quality steels that undergo electrolytic coating to achieve specific surface characteristics and protective qualities, making them suitable for further processing and specialized end uses.
Key Topics
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Product Types and Dimensions
- Covers both single cold-reduced ECCS (thickness: 0.150 mm to 0.600 mm) and double cold-reduced ECCS (thickness: 0.100 mm to 0.390 mm)
- Applies to coils and sheets cut from coils, generally in minimum rolling widths of 600 mm (or 500 mm by agreement)
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Coating Processes
- Specifies coating via either the hexavalent or trivalent chromium process, resulting in a duplex layer: metallic chromium adjacent to the steel and a hydrated chromium oxide or hydroxide top layer
- Minimum and maximum coating masses for both total chromium and chromium in oxide are clearly defined
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Surface Finishes
- Multiple surface finishes are available: bright, fine stone, stone, and matt, each with their own visual and tactile properties
- Finish type influences downstream printability and lacquer adhesion
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Mechanical Properties and Test Methods
- ECCS grades are classified by either hardness (Rockwell HR30Tm) or tensile properties (yield strength, proof strength)
- Test methods and acceptance criteria for hardness, tensile strength, and flatness are provided
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Dimensional and Shape Tolerances
- Tight tolerances on thickness, width, length, edge camber, and flatness to ensure compatibility with high-speed, automated manufacturing processes
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Purchaser's Information
- Orders must specify grade, surface finish, dimensions, annealing method, and intended application
- Options exist for further buyer-manufacturer agreement on rolling width, coating process, and other special requirements
Applications
Electrolytic chromium/chromium oxide-coated steel produced in accordance with ISO 11950:2026 offers critical performance in the following sectors:
Related Standards
Manufacturers and users of ECCS in compliance with ISO 11950:2026 should also consider the following related international standards for complementary requirements and testing methods:
- ISO 404 - Steel and steel products - General technical delivery requirements
- ISO 6508-1 - Metallic materials - Rockwell hardness test - Part 1: Test method
- ISO 6892-1 - Metallic materials - Tensile testing - Part 1: Method of test at room temperature
- ISO 10474 - Steel and steel products - Inspection documents
Summary
ISO 11950:2026 establishes clear and robust requirements for the manufacture, delivery, and quality control of cold-reduced electrolytic chromium/chromium oxide-coated steel. By adhering to this standard, producers and purchasers ensure consistent product quality, process compatibility, and a reliable basis for international trade in high-performance steel packaging materials.
