Cutting data for machining graphite — speeds, feeds, cutter geometry, dust extraction and the tool wear behaviour that makes graphite different from metal.
Complete reference tables and engineering data for graphite machining. All values verified against ISO, ANSI, and manufacturer standards.
Graphite is machined primarily for EDM (Electrical Discharge Machining) electrodes. It is abrasive, brittle, and produces conductive dust that can damage machine electronics. This guide covers the essential parameters for successful graphite machining.
Graphite is easier and faster to machine than copper (the alternative electrode material) and does not melt at EDM temperatures -- it sublimates directly from solid to gas. It also has lower wear ratios than copper in many applications. The downside: graphite is messy (dust), brittle (sharp edges are challenging), and requires diamond tooling.
Strongly not recommended. Graphite dust infiltrates way covers, ball screws, and control cabinets. The dust is conductive -- it can short circuit boards and cause erratic servo behaviour. Dedicated graphite machines have sealed linear guides, positive-pressure control cabinets, and built-in dust extraction. If you must share, protect the machine thoroughly and clean meticulously between jobs.
Diamond-coated carbide end mills: good cost-performance for general graphite machining. The diamond film (CVD, 5-20 um thick) provides excellent abrasion resistance. PCD (polycrystalline diamond) inserts/end mills: solid diamond cutting edge, ultimate tool life (5-10x diamond-coated), best for high-volume electrode production. PCD costs 3-5x more but can machine thousands of electrodes per tool.
Use diamond-coated or PCD tooling exclusively. Machine dry with high-velocity dust extraction. Set speeds 3-5x higher than for steel. Use climb milling and avoid sharp internal corners. Protect your CNC machine from graphite dust -- it is conductive and abrasive to machine components.
Continue with closely related resources from the machining reference library.
Use the calculator freely. If the result points to a tooling or process problem, we can source the exact carbide tooling you need from vetted factories in China. Compare factory-direct pricing.
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CUTTING GRAPHITE? Graphite wears edges by abrasion, so grade selection is the whole game. See how a wear-resistant grade claim is verified.
We source carbide cutting tools from China for job shops. We do not own a factory, which is why we can quote your drawing against two or three plants that actually run your material.
Cutting formulas with the units worked through · Speed and feed starting points for all six ISO material groups · How to read a carbide grade past its ISO code. 12 pages.
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