How to choose electrodes for your EDM machines? Graphite Electrodes or Copper Electrodes

Machining   Speed

Fast (significant advantage in   rough machining, 3-5 times faster than copper)

Relatively   slow

Electrode   Wear

Low (can achieve "near-zero   wear" in rough machining)

Relatively   low (less wear during fine machining)

Surface   Quality

Average (can   achieve VDI12, Ra0.4μm)

Excellent (can achieve mirror finish   Ra<0.1μm, more stable surface quality in fine machining)

Machining   Precision

High (low thermal expansion   coefficient, less prone to deformation)

Relatively   high (but thermal expansion coefficient is 4 times that of graphite, prone to   deformation at high temperatures)

Machinability

Excellent (low cutting resistance, easy   to clear corners, no burrs)

Poor (soft   texture, prone to sticking, and burr formation)

Weight

Light (density is about 1/5 that of   copper)

Heavy

Cost

Stable   material price, high processing efficiency, potentially lower overall cost

Material is   a non-renewable resource, with a rising price trend

Applicable   Scenarios

Large and   medium-sized electrodes, rough machining, complex shapes, deep and narrow   ribs

Small and   medium-sized electrodes, high surface quality requirements, precision   machining, ultra-precision machining (e.g., mirror finishing)