Knoop hardness tester

Testing with Knoop Hardness Tester

The Knoop hardness tester applies the Knoop hardness test. This is a microhardness test; a low force test for determining mechanical hardness. The Knoop hardness test is mainly used for testing very brittle materials or thin sheets, for when only a small indentation can be made. The Knoop hardness testers from INNOVATEST are made in the Netherlands. With us you will find the largest range hardness testers and you can count on the best quality and service.

Knoop vs. Vickers

The Knoop resulting indentation is not symmetrical like Vickers indentions and will be subject to more variations of the resulting hardness values when testing to Knoop scales, especially below 200 gf.

How does the Knoop hardness tester work?

Knoop hardness is not typically being used to define bulk hardness, except at 500 gf where standards such as ASTM provide conversions of Knoop results to other hardness test scales. Also, Knoop tests are not typically performed at test forces above 1000 gf, although particular circumstances and or materials may need higher forces like 2 and 5 kgf. Expect larger variations in results at these loads. The Knoop diamond indenter is designed with a significant difference between the long and short Knoop diagonals, which is often better suited for determining variations of hardness over very small distances compared to the Vickers indenter.

Preperation of Knoop Hardness Tester

The success of the sample preparation procedure in removing damage caused by elements such as corrosion and / or scratches, can and will influence the test results. This problem becomes more critical as the test force decreases.

Formula Knoop hardness tester for the calculation of hardness;

Advice from our specialists

In the early stage of your interest in our hardness testers, our sales team will gather the information to offer a product adapted to your individual requirements and testing needs. We welcome requests for customized solutions whether it be software and/or hardware to best suit our testers for your needs. Our team takes great pride in working with your team to develop and supply the right configuration of the Knoop hardness tester for your application. 

Would you like to receive more information or do you have a specific question about the Knoop hardness tester or one of our other hardness testers such as the:

Please do not hesitate to contact us. We are happy to help you.


Knoop hardness tester