At Kadco, the tools we use differ substantially from conventional milling and drilling tools. We use mills to produce features that would be impossible to make on our surface grinders. We have a substantial number of three-axis CNC mills, all of which our two skilled milling machinists can keep running simultaneously. We also employ a unique five-axis CNC machining center, originally intended for grinding precision optics, to machine workpieces that would be prohibitively complicated to make on our three-axis mills.
The tools we typically use for milling have more in common with the wheels we use on our surface grinders than with conventional endmills. These tools generally consist of a steel shank and thousands of diamond particles in a single layer on one end, embedded in a layer of electroplated nickel. Rather than cutting with sharpened teeth, the individual diamonds remove tiny chips from the workpiece.
Recently, advances in the synthesis of binderless polycrystalline diamond (BL-PCD) and use of ultrashort pulsed laser ablation have allowed the creation of tools with complex cutting geometries, much like that of conventional tools. These BL-PCD tools create new possibilities for milling threads, cutting more accurate contours, and drilling smaller holes in hard materials.
We often use core drills—a hollow metal cylinder, plated with diamond on one end, through which we run pressurized coolant—to create deep holes in materials harder than that which conventional tools are made from. A substantial benefit of the hollow drill is that the material from the center of the hole, which would be wasted with conventional tools, is usable as cylindrical stock.
Yes, grinding wheels! The exact ones we use on our surface grinders can be used with our five-axis machining center. This allows the higher material removal rates one would associate with a purpose-built grinder (in ceramics) as well as the more complex geometries and setup flexibility offered by a five-axis mill.