In the previous study, by the same authors, titled "A new process damping model (PDM) for chatter vibration (Measurement, 44 (8) (2011) 1342-1348)", a new approach has been presented for obtaining process damping ratios (PDRs). This PDM has been constituted on the basis of the shear angle () oscillations of the cutting tool and the alteration of the penetration forces when they penetrate into the wavy surface. Variation and quantity of PDR are predicted by reverse running analytical calculation procedure of traditional Stability Lobe Diagrams (SLDs). In this study, firstly, how the PDM in previous study results with different materials such as AISI-1050 and Al-7075 are examined. Then, two problems are solved: how much of the total PDR of cutting system is caused by the tool penetration and how much is caused by () oscillation? Finally, verification of PDR values and PDM are performed by energy equations. © 2012 Elsevier Ltd. All rights reserved.