NBN T22-105

Introducing NBN T22-105 – Industrial Physics

NBN T22-105 is a national hardness testing standard used to inspect coatings using a pendulum hardness testing approach.  

The hardness and flexibility of a coating are opposing functionalities that must be optimized to achieve the right balance for a desired application. A coating should both offer a high hardness, while having elastic properties too.  

While it’s often categorized as a hardness test, the pendulum impact test actually assesses the elastic and visco-elastic behavior of coatings.  

What’s involved in NBN T22-105 pendulum hardness testing?  

The pendulum rests on the coating surface with two balls and is set into oscillation. The faster the amplitude decreases, the softer the coating. The damping of the pendulum movement is based on the delay of the elastic recovery of the coating after it has been deformed by the contact balls. 

This method is suitable for objective evaluation of both single-layer and multilayer systems. It can be used in the development of new coatings as well as in quality control for batch testing. 

NBN T22-105 pendulum hardness testing

A pendulum resting on a coated surface is set into oscillation, and the time for the oscillation amplitude to decrease by a specified amount outlined in this international standard is measured. The shorter the damping time, the lower the hardness. 

The NBN T22-105 pendulum hardness testing standard provides a paint hardness testing approach with two pendulum hardness testing techniques.   

König and Persoz pendulum hardness testing

While pendulum hardness testers operate on the principle that the amplitude of oscillation of a pendulum touching a surface decreases more rapidly on softer surfaces, they vary in dimensions, period and amplitude of oscillation. 

As such, the König and Persoz hardness testing methods differ in the period and amplitude of the oscillation. The Persoz hardness test measures the time taken for the amplitude of oscillation to decrease from 12° to 4°, while the König hardness test measures from 6° to 3°. 

Industrial Physics NBN T22-105 testing equipment

So, how can Industrial Physics improve your NBN T22-105 pendulum hardness testing? 

TQC König Pendulum for hardness testing
The König pendulum consists of an open framework connected by a cross-bar with two balls attached to the underface. The lower end of the framework is formed into a pointer and a weight sliding on a vertical rod and attached to the cross-bar is used to counterpoise the pendulum. The damping time, in seconds, for the oscillation amplitude of the König pendulum to decrease from 6°to 3° is measured.  

TQC Persoz Pendulum for hardness test 

The Persoz pendulum is made from an open framework with an upper cross-bar that has two stainless steel balls inset to form a fulcrum. It also has a lower cross-bar that forms the pointer. The damping time, in seconds, for the oscillation amplitude of the Persoz pendulum to decrease from 12°to 4° is measured. 

Need paint testing solutions? Get in touch

We’ve learnt a thing or two about paint testing and hardness testing over the decades. Now Industrial Physics is recognized as a brand that likes to bring new, innovative pendulum impact testers to market. 

We like to share our knowledge. Across the knowledgebase section of our website we publish lots of blogs on related subjects. First up, why not try this blog that explores the different types of impact testing equipment. Then you could try this one which describes how to protect your coating performance with scratch hardness testing. 

If you have any questions about NBN T22-105 pendulum hardness testing and how we can help you with other aspects of your inks and coatings inspection, then just get in touch!
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