Investigation of the Effects on Screw Thread of Infeed Angle during External Threading

This paper presents the effects of the infeed angles in terms of the surface analysis and cutting force components on thread quality in the external threading operations. Threading operations were carried out on a CNC lathe by single-point cutting tools for 0°, 14.5°, 15°, 27.5° and 30° infeed angles at the constant cutting speed of 100 m/min. The main cutting force and the radial force were determined as significant force components in terms of energy consumption in threading processes. It was also determined that the microhardness increased toward the thread root from the thread crest throughout the flanks. According to experimental results and the surface analysis, it was found that the optimum infeed angle was 30º in external threading.