What distinguishes a form mill from other milling cutters?

A form mill is distinct from other milling cutters primarily because it is custom-designed for producing specific shapes and profiles, often tailored to the requirements of particular parts. This customization allows the form mill to create complex geometries that are integral to the function of the finished part. For instance, it can be used to generate contours that would be difficult or impossible to achieve with standard milling cutters.

While it's true that form mills can be used for rough shaping, that attribute is not unique to them as other types of cutters can also perform this function. They are not limited to use on metal alone, as form mills can work on various materials, including plastics and composites, depending on their design and the cutting tools used. The fixed cutting dimensions of a form mill are also a characteristic found in other milling tools, so this does not uniquely define a form mill either. The key feature that truly sets it apart is its custom design for specific applications.