The standard “EN ISO 1460 Metallic coatings - Hot-dip galvanizing on iron-based materials - Gravimetric determination of mass per unit area”, developed by the International Organization for Standardization (ISO) and later published as a European standard within the scope of harmonization efforts, describes a method for determining the mass per unit area of hot-dip galvanizing on iron-based materials. Since knowing the surface area precisely is essential, this international standard is mainly applicable to shapes whose areas can be easily determined. For heavier samples, if the requirements of this standard cannot be met, the mass of the hot-dip galvanizing coating must be determined by another method.
This method is based on dissolving a coating on a surface with a known surface area in an inhibitory acid and determining the mass loss that occurs by weighing the sample before and after dissolution. Since knowing the surface area is essential, it is mainly applicable to shapes whose areas can be easily determined.
In principle, during the test, a hot-dip galvanized coating on a known surface is dissolved in an acid with an inhibitor, and the mass loss is determined by measuring the weight of the sample before and after the coating dissolves.
If necessary, the sample is degreased with an organic solvent that does not damage the hot-dip galvanizing coating, and then dried. Before stripping, the sample is weighed with an accuracy of better than 1 percent of the assumed coating mass.
The amount of solution should be measured so that there is at least 10 ml of solution per square centimeter of the sample's surface. The sample should be completely immersed in the solution at room temperature and allowed to sit until the coating is completely dissolved. The end of the dissolution process can be determined by the cessation of the hydrogen release, which is initially rapid. The sample should then be rinsed under running water and, if necessary, brushed to remove any loose matter adhering to the surface, immersed in alcohol, quickly dried, and weighed again with the precision described in the previous paragraph. After weighing, the surface area of the exposed surface should be determined with 1% accuracy.
In short, the EN ISO 1460 standard includes a precise, gravimetric (weight-based) test method for measuring the mass per unit area of hot-dip galvanizing coatings applied to ferrous materials (such as steel and iron). This standard plays a significant role in quality control, certification, and conformity verification in the galvanizing industry, as coating mass is directly related to corrosion protection performance and durability.
Hot-dip galvanizing provides excellent corrosion resistance by immersing cleaned steel in molten zinc, forming a metallurgical bond with protective zinc-iron alloy layers. The thickness (or rather, the mass) of this zinc coating determines its service life in various environments.
Standards such as EN ISO 1461 (coating requirements) specify minimum coating masses depending on material thickness and application. EN ISO 1460 provides a reference test method to verify whether the applied coating meets these minimum requirements.
This method is particularly useful in the following areas:
This method is applicable to hot-dip galvanizing coatings on iron-based materials. It requires accurate knowledge of the surface area being tested, therefore it is best suited for parts or samples with easily calculable geometries (such as flat sheets, simple shapes, wires). Complex or irregular shapes may require alternative methods.
The gravimetric method is destructive: the zinc coating is chemically stripped from a known surface area, and the mass loss is measured. The process generally follows these steps:
During sample preparation, degreasing is performed if necessary, and complete immersion is ensured (at least 10 ml of solution per cm² of surface area). Weighings should be performed with an accuracy of better than 1% of the expected coating mass, and the surface area should be determined with an accuracy of plus/minus 1%. When applied correctly, this method offers good repeatability.
This method remains the most accurate and peer-reviewed technique for determining the zinc coating mass in hot-dip galvanizing, providing reliable corrosion protection in construction, infrastructure, automotive, and many other sectors.
The EN ISO 1460 standard is essential because it provides the most accurate and reliable reference method. This accuracy is critical in an industry where the coating mass directly determines the corrosion protection life, structural safety, contractual compliance, and long-term durability of steel components.
Hot-dip galvanizing protects steel by forming a durable zinc coating that is sacrificially resistant to corrosion. EN ISO 1461 or equivalent standards specify minimum coating mass requirements (e.g., an average of 85 μm for steel thicker than 6 mm, which is approximately equal to 610 g/m2). Without a reliable way to verify whether these minimums are met, quality cannot be assured.
The gravimetric method, which involves chemically isolating zinc from a known surface area and measuring mass loss, is destructive but offers superior accuracy:
Non-destructive techniques, such as magnetic or electromagnetic measuring devices according to the EN ISO 2178 standard, are faster, cheaper, and allow for 100% inspection of parts. However, they have limitations. Galvanizing plants use magnetic measuring devices daily for process control. But when certification, third-party testing, or a customer rejects a batch due to an alleged inadequate coating, the EN ISO 1460 standard provides precise measurement.
In short, the EN ISO 1460 standard is based on the fact that the value of hot-dip galvanizing lies in its proven, long-term corrosion resistance, and that this resistance can only be reliably guaranteed by measuring the coating mass with the highest possible accuracy.
For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the EN ISO 1460 standard.
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