Testing

Hardness is a measure of materials’ resistance to permanent deformation when in contact with a harder material. Hardness tests are conducted to determine the hardness and mechanical properties of that material. They are important because these tests can predict a material’s behavior in service. For example, a very hard material will likely be less susceptible to scratches and wear than softer material. Hardness tests screen materials for properties such as abrasion resistance, ductility, and strength. As such, hardness testing is an essential tool for optimal material selection, research and development processes, and quality control.

There are multiple methods available for accomplishing hardness tests. The four most common types, however, include the Rockwell, Vickers, Knoop, and Brinell hardness tests.

Rockwell Hardness Test

This test evaluates hardness by pushing an indenter at a specific load into contact with the material being evaluated. Testers can then quickly measure that indentation depth utilizing a direct readout to determine material hardness. While this test is a good fit for metals, plastics and other materials are sometimes the subjects of Rockwell hardness testing.

Vickers Hardness Test

The Vickers hardness test works on metals as well, but is applicable for all types of solid materials. Rather than measuring depth, this test instead determines hardness by looking at the length of diagonal indents. Testers will use a diamond pyramid indenter, again at a particular load, to press into the test material and then perform an optical observation of the diagonals. Comparing the results with a formula or table, testers arrive at the hardness value.

Brinell Hardness Test

The Brinell hardness test involves creating a fairly sizable indent in the material’s surface with a ball of tungsten carbide and then completing an optical measurement of the diameter of the resulting indention for identifying the level of hardness. This test is often used for evaluating metals like castings that have less hardness, and it is well suited for measuring the hardness of large surfaces possessing a grain structure that is nonuniform or rough.

Northern Heat Treat provides various hardness testing services to ensure that your parts meet the required hardness specifications and perform as intended. We offer A scale, B scale, and C scale Rockwell testing; Brinell testing; King testing; and microhardness testing.

If you are looking for quality hardness testing services, the team at Northern Heat Treat is here to help. We have the resources, staff, and experience to get the job done right. In addition to testing, we have a plethora of capabilities to best serve you, including air, case, induction, and through hardening; straightening; annealing; and stress relieving. By working with us, you can be confident that your parts will meet your requirements. At Northern Heat Treat, we emphasize quality control, and we work hard to make sure that parts have consistent hardness for superior customer satisfaction. Contact us today to learn more about our hardness testing and other services.