An indenter of hardmetal ball (diameter D) is forced into the surface of a test piece and, after removal of the test force (F), the diameter of the indentation (d) left in the surface is measured. The Brinell hardness is proportional to the quotient obtained by dividing the test force by the curved surface area of the indentation. (The indentation is assumed to retain the shape of the ball, and its surface area is calculated from the mean indentation diameter and the ball diameter. 

Symbols and designation: 

Distance between indentation centre

The distance between the centres of two adjacent indentations shall be at least 3d. The distance of the edge of the specimen (test piece) to the centre of each indentation shall be a minimum of 2.5d. 

 

Tolerable value of repeatability and tolerance of error. 

d : mean of the diameters of five indentations
H : hardness of reference block
 

Hardness symbol and testing conditions 

Above sharing just for your reference. When you’re interested in investing a hardness tester to improve your quality process, select a supplier who offer a quality service and meet your specific needs.

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