This paper presents the results of an investigative study on the chip side-curling mechanism and the associated variable tool-chip contact in turning operations. The effect of various cutting and tool geometry parameters such as depth of cut-nose radius ratio, feed, inclination angle, etc. on chip side-curling are established in a hierarchical manner. The importance of variable friction at the tool-chip interface along the developed length of the cutting edge is shown from the experimental observations of the tool-chip contact area using a SEM analysis. The significant influence of the radial cutting force component on the resultant chip side-curl is established using a high speed-filming analysis of comparative experiments in tube and bar turning operations.