How can we identify the frequency range for the surface roughness & waviness?

I have done the experiment In face milling and the z-axis acceleration signals of the cutting tool (time domain) have been recorded. Now I have converted these time domain acceleration signal into the Frequency domain(by FFT), I want to select the data which its frequency range is related to the surface roughness and waviness. so I can filter the unwanted data, at the same time, I know the Feed rate Frequency and the tooth engagement Frequency. 

the question is, How can we identify the frequency range for the surface roughness & waviness? so I can extract them from signals.

Thanks for the helping. Regards.