ISO 1520

Introducing ISO 1520 – Industrial Physics

ISO 1520 is an international ISO standard for assessing the resistance of a coating of paint, varnish or related product to cracking or detachment from a metal substrate.  

This ISO standard method is known as the ‘cupping test’. It recreates the impact of gradual deformation by indentation under standard conditions. 

Types of ISO 1520 cupping test

The ISO 1520 cupping test can be carried out as a ‘pass / fail’ test by testing to a specified depth of indentation to assess compliance with a particular requirement. It can also be undertaken by gradually increasing the depth of indentation. This will determine the minimum depth at which the coating cracks or becomes detached from the substrate…or both!  

If you want to inspect the deformation resistance of a multi-coat system then you also have two choices: each coat can be tested separately or the complete system may be tested. 

The ISO 1520 cupping test process

So, how do you perform a cupping test to ISO 1520 standards? 

The first part of the ISO 1520 cupping test involves applying the paint, varnish or product you want to test evenly and consistently to flat panels of a uniform surface texture.  

After drying and curing the elastic properties of the paint film are determined. You do this by placing the coated panel between two rings – the retaining ring and the drawing die.  

The cupping test panel is then pushed by a hemispherical indenter at a steady rate into the test piece. This should then form a dome shape with the coating on the outside.  

The deformation is increased – either to a specified depth, or until the coating cracks, or detaches from the substrate. Finally the cupping test result is assessed. ISO 1520 specifies that the test results should be reported as either: 

• Whether or not the coating on the test panels passed the specified indentation depth 
• The maximum depth of indentation at which the coating passed, obtained from the calculation of the mean of three valid results (triplicates) and to the nearest 0.1mm 

Cupping tests should be carried out in triplicate at (23 ± 2) °C and a relative humidity of (50 ± 5) %. 

What’s covered within the ISO 1520 standard document?

The ISO 1520 cupping test documents include the following sections:  

• Scope of the document and the principle of the method 
• Guidance on sampling and preparation and conditioning of cupping test samples  

• The apparatus to use 
• The cupping test procedure to follow   
• How to calculate and express your cupping test results 

ISO 1520 testing devices

So, how can Industrial Physics improve your ISO 1520 testing? 

TQC Sheen Automatic Cupping Tester 

The TQC Sheen Automatic Cupping Tester performs cupping tests on coated steel panels. It will help you to determine the resistance of paint, varnish or related products to cracking or detachment from a metal substrate and it’s ideal for testing to ISO 1520 standards.  

TQC Sheen Manual Cupping Test 

Our industry-leading manual cupping tester will inspect the resistivity of coatings at various stages of deformation in accordance with ISO 1520 and DIN-EN 13523-6 standard requirements. The built in gear-box minimizes the manual force which is required to deform the test panel, allowing it to perform a smooth deformation. The degree or deformation is digitally displayed at a resolution of 0.01mm. 

Your global test and measurement partner for ISO 1520