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
Barcol hardness test and 90B. A measurement of 60B is roughly equivalent to a Shore hardness of 80D or a Rockwell hardness M100. As defined in ASTM D 2583 the scale divisions from 0-100 should each indicate a depth of 0.0076 mm or the equivalent 0.0003 inches. Barcol hardness test The Barcol hardness test characterizes the indentation hardness of materials through the depth of penetration of an indentor, loaded on a material sample and compared to the penetration in a reference material. The method is most often used for composite materials such as reinforced thermosetting resins or to determine how much a resin