Why should graphite electrode cost be evaluated as part of the total EDM job cost?

The raw purchase price of the electrode material typically accounts for only a small fraction of the total EDM job cost. Looking at material cost outside the context of the total operation is meaningless because fabrication time, EDM cutting time, shop labor, and tool wear rates depend far more on the selected electrode material than on any other factor. Accurately assessing job profitability requires an objective cost-performance analysis based on the specific material properties and how that graphite grade performs against the workpiece metal.