Brinell hardness test

I Brinell hardness testers allow employing heavy loads in quite simple and rugged structures The indentation diameter is read with an optical system (eyepiece or microscope). Testing is possible even if positioning of the piece is not perfect, because the Brinell test is not sensitive to deflection of the test piece. It is possible to derive the tensile strength value simply by multiplying the Brinell hardness number by a certain factor, changing according to the test material. In spite of the heavy load, an accurate surface preparation is needed to obtain reliable results. For this reason, the Brinell test cannot be considered a quick test and it is not suitable for testing of high volumes.

To overcome this problem, Ernst has designed a series of Brinell hardness testers operating according to Rockwell method, but using Brinell penetrators and loads. In this case, the difference of penetration between preload and load gives the indentation measure. Test results are directly shown on the display or on the dial indicator in Rockwell numbers that will be converted in Brinell numbers using the proper table. This method is more convenient in the case of high volume testing, as it allows avoiding the optical reading and the surface preparation required by the classic Brinell hardness testers. To increase the accuracy in the case of high volume testing, the range of Ernst Brinell hardness testers give the operator the possibility to introduce a new and temporary calibration of the Brinell scale, based on Brinell test blocks, where the indentation has been made by classic Brinell testers.