When procuring CNC tools, you must prioritize Substrate Material (such as Tungsten Carbide, HSS, or Cermet) and Coating Technology (like TiAlN, AlTiN, or DLC) which directly impact heat resistance and tool life. Ensure the Hardness Rating (HRC) of the tool is compatible with your workpiece material; for example, machining hardened steel requires tools with a rating of HRC 55-65. Additionally, verify the Shank Diameter Tolerance (typically h6) to ensure precise fitment in tool holders and minimize run-out.