Graphite Machining Terms

Graphite Machining Terms

Angstrofine - The most advanced type of EDM graphite. Angrostofine is used when fine detail and a smooth finish is required.

Billet - An uncut block of graphite produced by the manufacturer that ranges from two to seven square inches. A billet is commonly used for longer projects.

Breakthrough - The exit end of a through-hole cavity which occurs at the moment of completion.

Carbon - An abundant element of natural occurrence, often used instead of the word graphite. Graphite is a type of the element carbon.

Coke - A processed form of coal. Processed coke burns more steadily and is stronger than metallurgical coke.

Composite - Two or more materials combined. An example is copper graphite, which is a metallic/carbon composite.

EDM - Electrical Discharge Machining; a process in which metal is removed through burning or erosion instead of through cutting.

Electrode - A tool used in EDM which mirrors the desired shape. The electrode must be made out of materials that can carry an electric current.

Filler - The carbonaceous particles in manufactured graphite comprising the base aggregate in an unbaked green-mix formula.

Flash - Thin fin or web of metal extending beyond the confines of the casting, usually along the joint line as a result of poor contact between cope and drag molds.

Grain - Referring to a region in a carbon or graphite body that is identifiable as being derived from a particle of filler.

Horn Gate - Curved gate in the shape of a horn arranged to allow entry of molten metal at the bottom of the casting cavity.

Isotropic - Having uniform properties in all directions. The measured properties of an isotropic material are independent of the axis of testing.

Machined - To shape, cut or finish a product by the use of a machine.

Premium Graphite - A material with a particle size of five microns or less. 

Transducer - Changes one form of energy into another; in EDM it is used to change electromagnetic force into mechanical force for the machining of graphite. Although there is sound produced when machining graphite, it is too high pitched for most human hearing.

Trim Die - Die used for shearing or trimming a workpiece.

Workpiece - Material that is being machined. The material will continue to be operated on until it is a replica of the original.