Why we can machine graphite with Diamond tools

Graphite has specific properties that make machining a challenge. It’s strong, but also brittle, and is susceptible to chipping if not handled properly. Cutting Graphite (or carbon) is different from cutting Metals. Metal exerts plastic deformation when a tool edge cuts it producing a curl or chips. When graphite is machined small powder-like particles separate from the work piece as a result of brittle fracture caused by the stress produced by the cutting tool edge. Graphite machining can be challenging. Especially if you are not prepared to work with its unique and messy properties.

Sometimes people misunderstand the phenomenon that carbon can be dissolved in steel, so that it is not possible to machine steel with diamond or diamond coated cutting tools. Carbon atoms from the cutting material dissolve into the material being machined. With dissolved we just mean that the carbon from our cutting material fills up the spaces between the atoms in another material. So we can say that the atomic structure of a certain material has room between their atoms.