The main purpose of this research is to study the analysis of the screw thread machining process for micro-type circular rods. During the analysis, the SUS304 stainless steel micro-type circular rod is used to analyze the micro thread machining process for the circular rod that will be fabricated according to varied outer diameters (Ø1.9mm, Ø1.94mm and Ø2mm), varied pitches (0.25mm and 0.4mm), and specific friction factors (0.1, 0.2, 0.3, 0.5 and 0.7). Through the micro material parameters with scale factors being corrected, the finite element analysis is conducted in order to learn about the effect of pitches and friction factors on the screw threads of the micro-type circular rod during the machining process. During the research, the finite element analysis was also conducted through the use of full integration rule and by coupling the shape function, as being inferred from the 3D tetrahedral element with 4 corner nodes, in the stiffness matrix. This research focuses on the simulation of comprehensive forming resume data, stress/strain distribution and thread shape distribution relating to the thread machining process for the micro-type circular rod. In the meantime, the micro-type circular rod screw thread machining die is also designed for carrying out the micro-type thread machining experiment for the SUS304 micro-type circular rod. The outcome is also compared with the simulation result to verify the reliability of the aforesaid analysis method. During the research, the difference between traditional material parameters and that of the corrected micro dimensions is also analyzed with the result provided below: The simulation result of the corrected material parameters indicated that the maximum principal stress tends to grow along with the enlarging of the pitch, but there isn’t a visible difference between the maximum principal strain and the material parameters being used before and after the modification. When the friction factors are changing during the micro-type circular rod screw thread machining process, its torsional, stress, and strain force tends to grow along with the increase of friction factors.

The main purpose of this study is to analyze the screw thread machining process for microtype circular rods of SUS304 stainless steel. During the analysis, micro-type circular rods with various outer diameters (1.9, 1.94, and 2 mm), pitches (0.25 mm and 0.4 mm), and friction factors (0.1, 0.2, 0.3, 0.5 and 0.7) are fabricated. Owing to the micro scale of the thread, the scale factor of the material should be corrected, and finite element analysis is conducted to determine the effect of the pitch and friction factor on the screw threads of the micro-type circular rods during the machining process. The finite element analysis uses a full integration rule to couple the shape function, which is inferred from the 3D tetrahedral element with four corner nodes used in the stiffness matrix. Then, we simulate the comprehensive forming history and determine the stress/strain distribution and thread shape distribution relating to the thread machining process for the micro-type circular rod. A micro-type circular rod screw thread machining die is also designed to carry out an experiment on micro-type thread machining for SUS304 micro-type circular rods. The result is compared with the simulation result to verify the reliability of the analysis method. The difference between the uncorrected material parameters and the corrected microscale dimensions is also analyzed. The corrected material parameters indicate that the maximum principal stress sensed in the experiments increases with the pitch. During the microtype circular rod screw thread machining process, the torque, stress, and strain increase with the increase in the friction factor.