Electrical discharge machining (EDM) is a machining method in which electrical discharge is repeated between an electrode and metal (such as mold material), and the resulting heat is used to melt the metal and create a shape. Today, the commonly used EDM wire diameters range from 0.1 to 0.3 mm due to processing machinery restrictions. Previously, 0.3 mm wire was considered thick, but its breaking load limited machining efficiency. When a large current was applied to process large workpieces or reduce machining time, the wire often broke due to heat. Additionally, it has recently become necessary to improve the surface accuracy of finish machining processes (reducing surface roughness). Therefore, electrical discharge performance must be improved, and wire diameter must be increased to shorten machining time and improve surface accuracy at the same time.

The HBZ-B40 EDM wire for electrical discharge machining developed by Proterial has a wire diameter of 0.4 mm, which achieves a breaking load that is approximately twice that of the commonly used wire diameter of 0.25 mm. In addition, the increased zinc content improves electrical discharge efficiency and electrical discharge performance. As a result, the new product achieves cutting speeds about 10% faster than previous 0.4 mm wires and improves surface accuracy, reducing surface roughness by approximately 7% (based on a demonstration conducted with Makino Milling Machine Co., Ltd.).