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Tolerancing Form Deviations for Rockwell Diamond Indenters



Jun-Feng Song, Samuel R. Low III, Li Ma


The spherical tip of Rockwell diamond indenters tends to be manufactured either a flat- or sharp-shaped surface because of the anisotropy property of the diamond. This can cause significant differences in the hardness readings. In order to control that effect, tolerances for form error deviations of Rockwell diamond indenters were specified in both ASTM and ISO standards. In this paper, experimental data on the effects of form deviations of Rockwell indenters are analyzed. Finite Element Analysis (FEA) is used to simulate the effect of form deviations on HRC readings. Theoretical analyses are verified by experimental results. Based on these results, as manufacturing and measurement techniques for Rockwell diamond indenters improve, it is suggested that a tighter tolerance be specified for the form deviations of Rockwell indenters used for calibrations of reference blocks.
Proceedings Title
IMEKO TC3/TC5/TC20 Joint International Measurement Conference
Conference Dates
September 24-26, 2002
Conference Location
Cekke, GE
Conference Title
International Measurement Confederation. IMEKO Congress


ASTM E18-2000, diamond indenter, FEA, finite element analysis, form deviation, HRC, ISO 6508-3:1999, Rockwell hardness


Song, J. , Low, S. and Ma, L. (2002), Tolerancing Form Deviations for Rockwell Diamond Indenters, IMEKO TC3/TC5/TC20 Joint International Measurement Conference, Cekke, GE (Accessed June 13, 2024)


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Created September 1, 2002, Updated February 19, 2017