CI Confidence interval
Coef. Second order coefficient
Cont Constant
D Depth of cut, mm
F Feed rate, mm/rev
Fα (1, fe) Ratio at a significance level
fe The error degrees of freedom
neff The effective total number of tests
P P test value
R The number of confirmation tests
Ra Arithmetic mean value
S/N Signal to Noise ratio
T T test value
TiAlN Titanium aluminum nitride
TiCN/Al2
O3
Titanium carbo-nitride / aluminum oxide
Ti(C,N,B) Titanium carbo-nitride-boron
V Cutting speed, m/min
Ve The error mean square