Improving performance thread turning cutters with ceramic plates

Despite many well-developed processes of high-pressure forming threads on the details of mass production, in some cases it is necessary to cut the thread cutter. Such cases include threading on thin-walled workpieces or high hardness, threading an asymmetrical structure. Leading companies are developing tools and release for these cases special threaded plate and allowed the program to calculate the cutting conditions and cutting allowance scheme depending on the pitch, and the hardness of the workpiece. Usually the threaded insert is made of cemented carbide, often with a hardening coatings. Profile feature of threaded plates is a small radius of curvature peaks associated with a step size of thread cutting. This leads to high mechanical and thermal loads to the top of the threaded plate and forces to provide reasonable resistance to reduce the cutting conditions: speed, speed associated with the workpiece, and the supply infeed per stroke. Recently, a plate of mineral ceramics based on alumina doped refractory metal carbides. These plates have a high heat resistance that allows you to increase the cutting speed. However, in the literature there is practically no information on the use of mineral ceramics plates for threading highly durable blanks. The paper presents the results of experiments on thread cutting with ceramic plates on steel billets of high hardness (HRC 52...55). Shows the effect of a negative rake angle, the values of penetration and cutter infeed into components of the cutting force. It is proved that the optimization of geometrical parameters of plates enables high-performance threaded onto the hardened workpieces made of high-strength materials, which, combined with a lower cost material plates promises significant economic benefits.