Glossary Terms

Tool is subjected to sudden, heavy loads and/or impacts, as in interrupted cutting. See interrupted cut.

Pressurized air system that cools the workpiece and tool when machining dry. Also refers to central pneumatic system.

Cold working a metal’s surface by metal-shot impingement.

Method of holding a round-shank cutting tool in a toolholder. To shrink-fit, the toolholder is heated in order to expand its bore, allowing a tool to be inserted. As the holder cools, the bore contracts around the shank to firmly hold the tool in place.

Mechanism typically used to feed parts into an assembly machine in a back-and-forth motion, inserting a part at the end of each stroke.

Industrial-grade, natural diamond. Not recommended for cutting ferrous materials because it tends to react chemically with them and break down. Also not recommended for interrupted cuts in hard materials. Replaced by polycrystalline diamond in many applications. See diamond; PCD, polycrystalline diamond; superabrasive tools.

Bonding of adjacent surfaces in a mass of particles by molecular or atomic attraction on heating at high temperatures below the melting temperature of any constituent in the material. Sintering strengthens and increases the density of a powder mass and recrystallizes powder metals.

Incomplete hardening of steel due to quenching at a rate slower than the critical cooling rate for the particular steel, resulting in the formation of one or more transformation products in addition to martensite.

Machining, normally milling, that creates slots, grooves and similar recesses in workpieces, including T-slots and dovetails.

Converts a milling machine’s rotary spindle motion into a reciprocating motion for machining keyways and slots.

Vertical or horizontal machine that accommodates single-point, reciprocating cutting tools to shape or slot a workpiece. Normally used for special (unusual/intricate shapes), low-volume runs typically performed by broaching or milling machines. See broaching machine; mill, milling machine.

Prolonged holding of a metal at a selected temperature to homogenize its structure or composition.