Indentation hardness test, performed with either 3 gf or 9 gf loads, preceded the development of microhardness testers using traditional indenters. In 1925, Smith and Sandland of the UK developed an indentation test that employed a square-based pyramidal indenter made from diamond. They chose the pyramidal shape with an angle of 136° between opposite faces in order to obtain hardness numbers that would be as close as possible to Brinell hardness numbers for the specimen. The Vickers test has a great advantage of using one hardness scale to test all materials.The first reference to the Vickers indenter with low loads was made
Meyer hardness test test is that it is less sensitive to the applied load, especially compared to the Brinell hardness test. For cold worked materials the Meyer hardness is relatively constant and independent of load, whereas for the Brinell hardness test it decreases with higher loads. For annealed materials the Meyer hardness increases continuously with load due to strain hardening. Based on Meyer's law hardness values from this test can be converted into Brinell hardness values, and vice versa. The Meyer hardness test was devised by Eugene Meyer of the Materials Testing Laboratory at the Imperial School of Technology, Charlottenburg, Germany, circa 1908.