List of symbols

Symbol	Name of the symbol	Unit
$ $	Hardened material 1	$\mathrm{ }$
$ $	Hardened material 2	$\mathrm{ }$
$C_E$	material coefficient	$\mathrm{\cfrac{1}{MPa}}$
$C_c$	coefficient according to load	$\mathrm{ }$
$D_1$	sphere diameter $ D_1 $	$\mathrm{mm}$
$D_1$	diameter of spherical socket	$\mathrm{mm}$
$D_1$	cylinder diameter $ D_1 $	$\mathrm{mm}$
$D_1$	diameter of cylindrical socket	$\mathrm{mm}$
$D_2$	sphere diameter $ D_2 $	$\mathrm{mm}$
$D_2$	cylinder diameter $ D_2 $	$\mathrm{mm}$
$E_1$	Young's modulus for $ E_1 $	$\mathrm{MPa}$
$E_2$	Young's modulus for $ E_2 $	$\mathrm{MPa}$
$F$	total force	$\mathrm{N}$
$HB_1$	hardness for $ HB_1 $	$\mathrm{HB}$
$HB_2$	hardness for $ HB_2 $	$\mathrm{HB}$
$K_D$	dimensional coefficient	$\mathrm{mm}$
$L$	length	$\mathrm{mm}$
$S_F$	safety factor	$\mathrm{ }$
$S_{y-1}$	the minimum yield strength for $ S_{y-1} $	$\mathrm{MPa}$
$S_{y-2}$	the minimum yield strength for $ S_{y-2} $	$\mathrm{MPa}$
$b$	diameter of sphere contact area	$\mathrm{mm}$
$p$	load per unit length	$\mathrm{N/mm}$
$ν_1$	Poisson's ratio for $ ν_1 $	$\mathrm{ }$
$ν_2$	Poisson's ratio for $ ν_2 $	$\mathrm{ }$
$σ_H$	allowable Hertz pressure	$\mathrm{MPa}$
$σ_c$	contact stress	$\mathrm{MPa}$