Glossary Terms

Process similar to conventional electrical-discharge machining except a grinding-wheel type of electrode is used. See EDM, electrical-discharge machining.

Process that vaporizes conductive materials by controlled application of pulsed electrical current that flows between a workpiece and electrode (tool) in a dielectric fluid. Permits machining shapes to tight accuracies without the internal stresses conventional machining often generates. Useful in diemaking.

Variation on electrochemical machining designed to remove burrs and impart small radii to corners. The process normally uses a specially shaped electrode to carefully control the process to a specific area. The process works on material regardless of hardness.

Variation on electrochemical machining that uses a conductive, rotating abrasive wheel. Chemical solution is forced between the wheel and the workpiece. Shape of the wheel determines the final shape.

Operation in which electrical current flows between a workpiece and conductive tool through an electrolyte. Initiates a chemical reaction that dissolves metal from the workpiece at a controlled rate. Unlike with traditional cutting methods, workpiece hardness is not a factor, making ECM suitable for difficult-to-machine materials. Takes such forms as electrochemical grinding, electrochemical honing and electrochemical turning.

Combination of electrochemical grinding and electrical-discharge machining. Material is removed by both processes. The workpiece and the grinding wheel never come into contact as in any other electrical-discharge-machining process. See EDG, electrical-discharge grinding.

In tensile testing, the increase in the gage length, measured after fracture of the specimen within the gage length, usually expressed as a percentage of the original gage length.

Reduction in the normal ductility of a metal due to a physical or chemical change. Examples include blue brittleness, hydrogen embrittlement and temper brittleness.

Suspension of one liquid in another, such as oil in water.

Milling cutter held by its shank that cuts on its periphery and, if so configured, on its free end. Takes a variety of shapes (single- and double-end, roughing, ballnose and cup-end) and sizes (stub, medium, long and extra-long). Also comes with differing numbers of flutes.

Operation in which the cutter is mounted on the machine’s spindle rather than on an arbor. Commonly associated with facing operations on a milling machine.

Limit below which a material will not fail.