An Experimental Study on Cutting Forces in the Threading and the Side Cut Turning With Coated and Uncoated Grades

The objective of this study is to obtain the cutting force components on the threading insert. The cutting force data used in the analysis are measured by a three-dimensional dynamic force dynamometer. The AISI 4140 and AISI 4340 low alloy steels are selected for the experiment on the threading and the side cut turning. The inserts used for testing is the TiAlN coated and uncoated grades. LT22NR35ISO type insert is used in the experiment. During the experiments, no cutting fluid and a constant spindle speed is used. The thread pitch and the depth of cut were kept fixed at 3.5 mm and 0.05 mm for the radial feed per pass, respectively. The study emphasizes on the effects on the workpiece material and the cutting tool grade of the cutting force components that occur during the threading. Also, these results are compared with the findings that are obtained during the side cut turning. It is determined that the measured primary cutting and radial forces during the threading are approximately three times bigger than those during the side cut turning, although feed forces during the threading are approximately 30 times lower compared with the side cut turning. The TiAlN coated WC/Co grade shows the best performance with respect to the cutting force components. The specific cutting forces are determined in order to understand the interference of chips that occur during the threading. With the increase in the cumulative radial feed, the corresponding specific cutting forces become higher. It is reasoned that the difference in the specific cutting forces results from the alteration of the interference of the flowing chips. The specific cutting forces decrease in the beginning of the threading and then increases with the cumulative radial feed. The results show that the interference of the chip flow influences the threading force components to a very large extent.