The Brinell hardness test for steel, involves impressing a ball
10 mm diameter, of hard steel or tungsten carbide, with a loading
of 3000 kilogrammes into the steel surface. The hardness of the
steel is then determined by measurement of the indentation.
A method for testing the hardness of metals by determining the depth
of penetration of a steel ball or a diamond sphero-conical indentor.
The value is read from a dial and is an arbitrary number related
to the depth of penetration. For testing hard steels, a sphero-conical
diamond is used with a 150 kg load, the result is read from the
black scale on the dial and is prefixed with the letter C.
The shore scleroscope measures hardness in terms of the elasticity
of the material. A diamond-tipped hammer in a graduated glass tube
is allowed to fall from a known height on the specimen to be tested,
and the hardness number depends on the height to which the hammer
A method of determining the hardness of steel whereby a diamond
pyramid is pressed into the polished surface of the specimen and
the diagonals of the impression are measured with a microscope fitted
with a micrometer eye piece.