Hardness testing began in the 1700s and continued into the early 1800s as Mohs developed his scratch test for minerals and other developing methods for scratch testing of metals. As the importance of metal hardness testing became realized, new hardness test methods continued to be developed in the later 1800s through the early 1900s. These methods moved away from the scratch test and towards measuring the penetration of an indenter into the specimen under force. Many variations of indenter shape and force were proposed, each attempting to overcome the deficiencies of previous methods. The industry settled on and fully adopted three of the most popular laboratory hardness methods: Brinell, Rockwell, and Vickers.
ASTM International[1], founded in 1898 as The American Society for Testing and Materials, is the primary standard developing organization in the Western Hemisphere. Brinell was standardized as ASTM E10 in 1924, Rockwell as ASTM E18 in 1932, and Vickers as ASTM E92 in 1952. These three standards all described stationary hardness testing machines intended to be installed in one place (e.g. metrology laboratory, quality inspection station) due to their design and construction. The robustness of these fixed-location machines has led to the respective standards to be used for material specifications. A main drawback to these methods is that they require the specimen under test to have opposite sides that are parallel and fit inside the machine. Industry quickly realized the need for a portable solution and developed other methods accordingly.