## 1 Introduction  
Amid the Fourth Industrial Revolution, commonly referred to as Industry 4.0, significant technological changes are taking place. Industries must undergo modernization processes not only to sustain but also to compete in the current market, both locally and, thanks to globalization, all around the world. Material removal processes have had to optimize all aspects of their operations to enhance efficiency, and within this broad category, milling machines play a fundamental role in the sector, particularly in the production of high-precision parts with superior surface finishes. Milling machines allow for the machining of surfaces and the creation of complex shapes in various materials, such as plastics and composites, though they are mostly used to work with metals. However, the significance of milling machines lies not only in their ability to perform precise and efficient cuts but also in their contribution to increasing productivity and reducing industrial costs [1]. Over time, these machines have evolved from simple manual devices to more sophisticated models managed by computer numerical control (CNC), thus improving precision and enhancing the repeatability of machining tasks to deliver unprecedented results. The accuracy of cuts depends on the machine's rigidity, the quality of guides and spindles, and the operator's skill or the CNC program's accuracy, as well as the wearing of the cutting tool [2]. Shaping a workpiece requires coordinated movement of the worktable and the rotation of a cutting tool, called a milling cutter, which removes material at high speed, cutting small chips until achieving the final product [3]. Milling machines are versatile and capable of performing diverse operations such as milling, drilling, boring, and threading. Cutting tools are essential for the machining process, enabling precise cutting, shaping, and finishing of parts. They are robust and efficient, capable of withstanding high forces and temperatures during milling. There are two main types: solid tools and interchangeable insert tools. Solid tools are made from a single piece of material, usually solid carbide or high-speed steel (HSS), known for their durability and precision; however, they require replacement or sharpening when worn, which can be highly costly and time-consuming. Interchangeable insert tools consist of a main body with replaceable cutting inserts, which can be changed when worn, reducing costs and minimizing machine downtime [4]. Inserts are small cutting pieces mounted on milling tools to perform precise cuts. They are utilized in disk cutters, slab mills, and grooving cutters for cutting flat surfaces, contours, and grooves, respectively. Choosing the right inserts and their proper use is crucial for optimal results in manufacturing and machining. Inserts are made from hard and wear-resistant materials, primarily tungsten carbide, ceramics, cermet (a mix of ceramic and metal), cubic boron nitride (CBN), and polycrystalline diamond (PCD). Tungsten carbide is the most widely used due to its high hardness and wear resistance, while ceramic inserts resist high temperatures, and cermet combines hardness and toughness. CBN and PCD inserts are used for specialized applications [5]. Inserts are classified based on shape, geometry, specific application, and the machined material. The shape determines the insert's cutting ability in different directions, with common shapes including square, round, triangular, rhomboidal, and hexagonal. Geometry influences cutting behavior, chip removal, and insert lifespan. Inserts are designed for various materials, such as steel, stainless steel, cast iron, non-ferrous metals, and composites, each requiring suitable properties to optimize cutting performance and minimize wear. The cutting angles of inserts in milling machines are fundamental for tool performance and lifespan. The main angles to consider are the inclination angle and the clearance angle, which affect cutting efficiency, chip formation, and tool durability.