PSZ = primary shear zone (with subscript AB)

SSZ = secondary shear zone or tool–chip interface (with subscript int)

A; B; C; m; n = yield strength; strength coefficient; strain rate coefficient; thermal softening coefficient; and strain hardening coefficient in the J–C model

$T_m$;$T_r$; T = melting temperature; room temperature; temperature

$V$; $V_c$; $V_s$ = cutting velocity; chip velocity; shear velocity

α; ϕ; λ; θ = rake angle; shear angle; friction angle at the SSZ; angle between resultant force R and the PSZ

w; t1;t2 = width of cut; depth of cut; and chip thickness

$l_{AB};h$ = length of the PSZ; the length of the SSZ (tool–chip contact length)

${\epsilon }_{AB}; \dot{{\epsilon }_{AB}}; {\epsilon }_{int};$$\dot{{\epsilon }_{int}}$ = strains and strain rates at the PSZ and SSZ

$C_0$ = Oxley constants (ratio of the shear plane length to the thickness of the PSZ)

$\delta$ = strain rate constant (ratio of the thickness of the SSZ to chip thickness)

$n_{eq}$ = strain hardening constant

$k_{AB}$ = calculated shear stress at the PSZ using the J–C model

$k_{AB}^{\prime }$ = calculated shear stress at the PSZ using a mechanics model

$k_{int}$ = calculated shear stress at the SSZ using the J–C model

${\tau }_{int}$ = calculated shear stress at the SSZ using a mechanics model

${\sigma }_N$ = calculated normal stress at the SSZ using a mechanics model

${\sigma }_N^{\prime }$ = calculated normal stress at the SSZ using the J–C model

$F_c$ = cutting force

$F_t$ = thrust force

$F_s$ = shear force at the PSZ

$N_s$ = normal force at the PSZ

F = shear force at the SSZ

N = normal force at the SSZ

R = resultant force