Plunge EDM

Plunge EDM, also known as ram EDM, cavity EDM and sinker EDM, uses a specially-shaped electrode to carve complex cavities in conductive metals. It can also form deep ribs and sharp inside corners, ideal for building molds. The first step of this process is to design the electrode, which is formed in the negative of the shape of the hole you want to create. This method can be used to create complex and even irregular shapes

The workpiece and the electrode are submerged in dielectric fluid. The electrode is slowly lowered (or sunk) toward the workpiece. As it gets close to the surface of the workpiece, a spark jumps the gap, eroding the workpiece. The electrode is slowly lowered until the desired cavity is created. The dielectric fluid helps to keep the workpiece cool and acts as an insulator. It also removes metal particles from the workspace.

When this process is completed, the part is removed from the dielectric fluid. It should be washed to remove any unwanted residues. The part can then be inspected to ensure that the cavity meets your requirements. Lastly, the part may need some post-processing before use. The EDM process may cause minor pitting on the surface of the part. It may require post-processing to achieve a smooth surface.