Glossary Terms

Cutter holder that permits rapid tool changes. Generally associated with automatic or semiautomatic machining operations. See toolholder.

Attachment for cutting gear teeth, usually in a straight line, but, when used in conjunction with universal spiral-index centers on a universal mill, it allows the machining of worms.

Large drill with an arm that pivots about a column to provide positioning flexibility and great reach and stability. See drilling machine, drill press.

Also known as the tool back rake, the angle between the tooth face and the radial plane through the tool point.

Angle of inclination between the face of the cutting tool and the workpiece. If the face of the tool lies in a plane through the axis of the workpiece, the tool is said to have a neutral, or zero, rake.

Process using a shaped electrode made from graphite or copper. The electrode is separated by a nonconductive liquid and maintained at a close distance (about 0.001"). A high DC voltage is pulsed to the electrode and jumps to the conductive workpiece.

Milling process in which the machine tool spindle is feeding simultaneously in an axial and radial direction.

Bacterial and fungal growths in water-miscible fluids that cause unpleasant odors, stained workpieces and diminished fluid life.

Movement on a CNC mill or lathe that is from point to point at full speed but, usually, without linear interpolation.

Molding process that allows the rapid molding of liquid materials. The injection-molding process consists of heating and homogenizing plastic granules in a cylinder until they are sufficiently fluid to allow for pressure injection into a relatively cold mold, where they solidify and take the shape of the mold cavity.

Rotating cutting tool used to enlarge a drilled hole to size. Normally removes only a small amount of stock. The workpiece supports the multiple-edge cutting tool. Also for contouring an existing hole.

1. Increasing the carbon content of molten cast iron or steel by adding a carbonaceous material, a high-carbon pig iron or a high-carbon alloy. 2. Carburizing a metal part to return surface carbon lost in processing; also known as carbon restoration.