HIT	instrumented hardness
P*	characteristic stabilized force corresponding to a specified penetration depth h*
P0*	characteristic stabilized reference force P*
Pi*	characteristic stabilized force P* corresponding to the i-th semi-cycle
h	indenter penetration depth
h*	constant penetration depth (4 μm) used to determine the characteristic parameter P*
ΔPi*	difference between stabilized forces ΔPi* = Pi* − P0* corresponding to the i-th semi-cycle
ΔU	relative deflection of the plate between the center and the outer supported edge
ΔUi	relative deflection ΔU corresponding to the i-th semi-cycle
ε	strain
εeb	equibiaxial strain
σ	stress
σeb	equibiaxial stress