In our work, we often buy cutting tools in this way, "buying milling cutters with specifications and hardness is enough." This is not only the procurement information for end mills, but also because many sales personnel do not have a professional understanding of cutting tools. Additionally, technical personnel lack theoretical knowledge of cutting tools and do not know what kind of cutting tools to process and what kind of materials. On the contrary, this procurement model has become mainstream, and many tool manufacturers mainly sell universal tools to meet different customer needs. However, this choice does not bring good economic efficiency to part processors. Today, the author will share with you the most important geometric parameters of a milling cutter. We need to know several parameters for purchasing an end milling cutter (1) Blade diameter of milling cutter (2) Blade length of milling cutter (3) Shank diameter of milling cutter (4) The full length of the milling cutter (5) Number of teeth for milling cutters