Mitsubishi Electric FA20-S

Mitsubishi's Digital AE (Anti-Electrolysis) technology applies bipolar pulse waveforms rather than unipolar pulses between wire and workpiece. Bipolar pulses prevent the DC electrolytic corrosion that conventional EDM generators can cause on sensitive materials like tungsten carbide and cemented carbide. This preserves workpiece surface integrity and prevents the white layer degradation that can affect part accuracy and tool life on carbide components.

The V350's expert system automatically selects cutting conditions — generator settings, feed rate, flushing pressure, and number of passes — based on the operator entering material type, workpiece thickness, wire diameter, and desired surface finish. This removes the need for manual generator parameter knowledge, enabling consistent results without years of EDM experience. Operators can also manually override any automatically selected parameter.

With 0.1 mm wire, the FA20-S can cut slots approximately 0.12 mm wide. Internal corner radii approach the wire radius plus a gap amount — approximately 0.06 mm with 0.1 mm wire. The smallest practical feature depends on wire diameter, workpiece material, and whether the geometry is accessible to flushing.

For most routine punch and die work, wire EDM has largely replaced profile grinding and jig grinding. The FA20-S achieves Ra 0.2 µm and dimensional accuracy suitable for precision blanking and forming dies. Complex 3D profiled punches and dies that were previously ground on jig grinders are routinely produced on wire EDM. Very tight tolerances (±0.001 mm) on critical die sections may still favor grinding.

The FA20-S and FA30 Advance share Mitsubishi's EDM heritage and Digital AE technology but differ in performance tier. The FA30 Advance offers a larger 600 x 400 mm travel, higher cutting speed, improved surface finish (Ra 0.1 µm), and a more advanced generator with enhanced skim pass capability. The FA20-S is the right choice for shops with predominantly smaller workpieces and moderate throughput requirements; the FA30 Advance suits shops needing larger capacity and higher finish quality.