•    Anodizing
One type of surface passivation. An oxide layer on the surface of a part is created by replacing some of the surface molecules with ions from an electrolyte bath.

•    B-Side
The B-side is often the inside or non-cosmetic side of a molded part. This side is usually formed by the core or B-plate of the mold tool in injection molding or pressure die casting.

•    Baffle
Flat or corkscrew shaped blades of metal inserted into the coolant channels of a mold tool to create a return coolant circuit within that channel.

•    Ball Nosed Endmill
In machining, a ball nosed endmill has a semi-circular cutting edge of a single radii.

•    Bosses
Projections or protrusions in cast or injected molded parts.

•    Bubblers
Typically thin, hollow tubes that are fitted into drilled holes of an injection mold tool to supply coolant in narrow or hard to reach areas.

•    Build Plate
Platform used in additive manufacturing upon which the layers of the part are built. Bull Horn

•    Gate
A type of submarine gate which gates on a face formed by the parting line. 

•    Bullnose End Mill
Similar to a standard endmill, these cutting tools have radiused corners of a known size. 

•    Bump Off
A shallow undercut area of a molded part that is able to be formed without lifters, sliders or handloads. 
 
•    CAD
Computer Aided Design. The use of computer software to create 2D and 3D digital models of an object in preparation for manufacturing.

•    CAM
Computer Aided Manufacturing. Producing objects with computer controlled machine tools using digital data.

•    Cascade Gating
A type of sequential gating using hot runners, in which a series of gates are automatically activated in succession to fill a mold cavity.

•    Cavity
Depression in a die casting or plastic injection mold tool, usually on the fixed or non-moving side of the mold. Typically forms the outside, convex and cosmetic face of the part.

•    Chip Size
The size of the metal chips that are created during CNC cutting operations.

•    Clamp Force
The amount of pressure applied between the 2 platens of a molding machine.

•    CMM
Coordinate Measuring Machine. This is a precision CNC controlled measuring device. Using special probes this machine can access and measure part features to a very high degree of accuracy on multiple axes.
 
•    CNC
Computer Numeric Control. The precise control of automated machine tools via digital instructions derived from CAD/CAM software.

•    Conformal Cooling
The cooling of a mold tool using internal channels created via 3D printing.

•    Cooling Time
A waiting period for die casting or plastic injection molding, allowing the part to solidify within the mold so that it can be safely ejected from the tool without deformation.

•    Cusp Height
In machining, the raised areas between adjacent passes of cutters.

•    Cycle Time
Production time required to complete one finished part in a molding operation and prepare for the next injection.

•    Datum
A reference point on one or more faces, surfaces or features of a part, from which all other dimensions are calibrated.

•    Debossed
Letters, logos or other graphic marks molded into a finished part, set below the surrounding surface.

•    Dielectric
Insulating fluid such as de-ionized water, used during electrical discharge machining (EDM).

•    Dimensions
Dimensions are measurable sizes of part features using standardized units.

•    DMLM
Direct Metal Laser Melting. A type of powder bed 3D metal printing using a laser to fully melt and bond successive layers of metal powder on a build platform.

•    Draft Angle
An angle applied to the design of a surface or side wall of a molded part, allowing it to be removed from an injection mold tool without damage.

•    DWG
From "drawing". A common CAD file format.

•    DXF
Drawing Exchange Format. A common CAD file format.

•    EDM
Electrical Discharge Machining. The removal of material from a workpiece using high-powered electrical current.

•    Ejection
The forced removal of a cast or injected part from a mold tool.

•    Electrode
A sacrificial conductor, usually of copper, which discharges high powered electrical current to erode the surface of a workpiece.

•    Embossed
Lettering, logos or other features raised from the surrounding surface.

•    End Mill
A cutting tool used in conventional milling. End mills have a flat cutting surface and sharp corners. See ball nose cutters, bull nose.

•    Engraving
Etching text, logos or other graphical features into a part face with an ultrasonically vibrating stylus.

•    Etch
Selective patterning or erosion of the surface of a part or mold tool to create a textured effect.