What are the four types of EDM electrode wear, and why is corner wear critical?

Electrode erosion is categorized into four distinct wear patterns: volumetric wear, corner wear, end wear, and side wear. Corner wear is the most critical of these four because the ability of the electrode to resist erosion at its edges and sharp corners directly dictates the final contours and tolerances of the finished cavity. Resisting erosion at these highly vulnerable points minimizes overall tool wear and maximizes total electrode life.

End wear measures the linear reduction in electrode length along the Z-axis feed direction. Corner wear describes the rounding and erosion of sharp leading corners and edges, and it can be higher than end wear because electrical charge concentrates at sharp geometry. Volumetric wear represents the total volume ratio of eroded electrode material compared to the volume of metal removed from the workpiece.