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ISO 2039-1 Test Standard Explained

Ball Indentation Hardness - ISO 2039-1

A 5 mm diameter steel ball is forced into a specimen with an initial load of 9.8 N and is increased to a specified load for 30 seconds. The depth of the resulting deformation is measured and the surface area of the impression is calculated. The hardness is then expressed as the load in Newtons divided by the surface area of the indentation in mm2. N/mm2=MPa.

Hardness values are displayed with an "H" (for "Hardness") followed by the test load in Newtons, a slash, and the test duration in seconds.

Ball Indentation Hardness Scales
Scale Test Load (N) Test Duration (sec)
H 49/30 49 30
H 132/30 132 30
H 358/30 358 30
H 961/30 961 30