f (τ)	Actual contact area between the tool and the workpiece
${\Delta }_i$	Allowance
Aos	Amplitude of the vertical oscillation
Ra	Arithmetic mean deviation of the assessed profile (surface roughness)
Vb	Belt speed
Pc	Clamping force
$X_i$	Code value of the i-th factor
vc	Cutting speed
ρ	Density
ß	Deviation angle of the cutting grain from the vertical position during grinding
$k_v$	Exponent taking into account the machinable material
$V_B$	Grain blunting area (flank wear)
GPU	Graphics processor
HB	Hardness
$v_s$	Longitudinal feed rate
Q	Material removal
MRR	Material removal rate
$q_i$	Material removal rate over the i-th grinding period
$X_0$	Natural value of the factor at the zero level
$\delta$	Natural value of the variation interval
N	Number of experiments
k	Number of factors
$q_y$	Number of levels
τ	Operating time of the tool till the resistance criterion (tool life)
$q_{Per}$	Performance index
p	Pressure
Py	Radial cutting force
$\epsilon$	Strain intensity
$\dot{\epsilon }$	Strain rate
σi	Stress intensity in the shear zone of the material being machined
$R{a}_1$	Surface roughness after the first grinding cycle
$R{a}_n$	Surface roughness after the n-th grinding cycle
$K_1$ $; K_2$	The coefficients accounting for the geometry of the cutting part of abrasive grains and the nature of metal yielding in the deformation zone
$T^0$	Temperature
${\sigma }_p$	Tensile strength of the grinding belt
$V_B$	Tool wear
Xn	Transition from the code expression of the factor to the natural value of the i-th factor
σD	Ultimate Stress
wos	Vertical oscillation frequency
Vw	Workpiece speed
σy	Yield Stress
X 1	Groups of the machined material
X 2	The type of machining determined by the size of the allowance P up to 1.00 mm and 0.05 mm
X 3	Strength groups of the grinding belt