Patent ID: 8655602

Claim:
A hardness test method, comprising the steps of: forming an indent by indenting a surface of a first sample with an indenter loaded with a predetermined load and detecting a displacement quantity of the indenter and a test force loaded on the indenter at a time of forming the indent to measure an indentation curve; calculating a work load by plastic deformation (Wp) from an area of an indentation curve obtained by the step of forming the indent; and calculating an estimation (HVe) of Vickers hardness of the first sample by using the work load (Wp), calculated at the step of calculating the work load, and a previously determined coefficient K in conformity with HVe =( K/Wp ) 2 , wherein the coefficient K is previously determined by an equation Wp′=K/√{square root over (HV)}, where HV is Vickers hardness of a second sample and Wp′ is a work load by plastic deformation of the second sample, the second sample being different from the first sample.