The Right Hardness Testing Method for Your Metals Application
The right hardness test method depends on the material being tested and the specific requirements of the application. Understanding the differences among the available options helps determine which method will give you the best results.
The most common methods used for testing the hardness of metals are Rockwell, Brinell, Vickers, and Knoop. Each of these methods employs different indenters and loads to measure the material’s resistance to plastic deformation.
Right off the bat, a key distinction between Rockwell testers and the Brinell, Vickers and Knoop testers is that the latter three use optical technology, while Rockwell does not—which generally makes it less costly, makes testing quick and easy, and the surface finish of the specimen is not critical. It is therefore, also the most commonly used method for metals testing on the U.S. market. The optical methods involve the use of a camera system, generally consisting of a digital camera, a light source, and lenses with various magnification strengths. Other factors to consider include: