Electrochemical machining (ECM) is a non-traditional machining process that removes metal through an electrochemical process rather than traditional cutting or grinding. In ECM, a power supply creates a voltage between the workpiece (anode) and tool (cathode) through an electrolyte, causing metal ions from the workpiece to dissolve and flow to the tool. This allows for complex internal and external geometries to be machined in hard metals. ECM is well-suited for mass production of parts with intricate shapes and difficult-to-machine materials due to its ability to machine stress-free and with high precision and surface finish.