CNC Machining of Graphite
Graphite is soft to cut and harsh on everything around it. The material machines quickly, but the dust it produces is conductive and abrasive, so the process — not the cutting — is what needs engineering.
Why it is hard to machine
Industrial graphite is produced in grades from fine-grain to isostatically pressed, with purity and grain size chosen for the application. It is electrically and thermally conductive, chemically inert, and stable at very high temperature in inert atmosphere — which is why it serves both as EDM electrode material and as a structural material inside semiconductor and vacuum furnaces.
Process controls that matter
Conductive, abrasive dust
Graphite dust is both abrasive and electrically conductive. Machining runs with dedicated extraction, and machines are protected so the dust never reaches guideways or electronics.
Chipping instead of burring
Graphite does not burr like metal — edges chip and grains pull out. Tool geometry, feed and fixturing are chosen to leave edges clean rather than to cut fast.
Tool wear is real
Although graphite is soft, its abrasive structure wears tooling. Sharp, wear-resistant tooling with predictable tool life keeps dimensions stable across a batch.
Cooling and cleanliness
Water-based coolant is generally avoided because of residue and contamination. Machining is typically dry or with minimal lubrication, with extraction doing the work.
Tolerances, inspection and documentation
Typical applications
EDM electrodes for mould and die work, semiconductor crystal growth and ion implantation parts, high-temperature furnace fixtures and heating elements, vacuum and glass-forming components.