Vocabulary and Glossary
Manufacturing and Machining Vocabulary
2D (Two-Dimensional)
A part is considered 2D if the Z-value of all internal features are set to “Air-Inside,” doesn’t contain edge effects, and only the top view is used. 2D parts with bends are also considered 2D.
3D (Three-Dimensional)
A part is considered 3D if it contains multiple Z-values, edge effects are selected or more than just the top view is used.
Axis
The direction along which the relative movements of a tool or workpiece occur. The three linear axes, occurring 90° angles relative to each other, are named X, Y and Z.
CAD (Computer Aided Design)
Computer applications that allow you to design mechanical parts and other items.
CAM (Computer Aided Manufacturing)
The use of computers to assist in manufacturing.
CNC (Computerized Numerical Control)
The computer control of the machines that fabricate parts.
The ratio of the friction force to normal force.
Creep
The deformation of a part over time when under constant stress.
Fillet
The deformation of a part over time when under constant stress.
Friction
Mechanical resistance of motion between two surfaces.
G-Code
The industry standard programming language that controls a CNC machine.
Galling
The wear that occurs due to adhesion between sliding surfaces.
Machining Center
Machine tools that are capable of automatically repeating operations such as drilling, reaming, tapping, milling, and boring multiple faces on a workpiece.
Machine Tool
A power-driven machine used to form or shape metal and other materials.
N/C (Numerical Control)
The process of controlling a machine or process by programming command instructions using code.
Nudge
The process of moving a line a fixed distance using the arrow keys.
Pitch
The nominal distance between centers of repetitive shapes.
Polyline
A line having more than one segment.
Roughness
The measurement that represents how smooth a surface is related to the height of the peaks and valleys.
Set Screw
A threaded fastener typically used to lock a sleeve, collar or gear on a shaft. Set screws are normally headless.
Shank
The section of a bolt between the head and the threads. Sometimes refers to the section of a cutting tool that is held.
Snap
The process of moving a line so it meets a key point on another line.
Static friction
The friction between two surfaces with no relative motion. It is the force required to start relative movement AKA stiction.
Tangent
The point on a curve that is parallel to a straight line.
Toolpath
The path a cutting tool travels to remove material and create shapes.
Torque
The measurement of twisting force applied to a fastener, shaft or other rotating member. It is often measured in newton-metres (Nm) or foot-pounds (ft-lb).
Tolerance
The acceptable variation in specified dimensions.
Z Axis
The third dimension that cannot directly be shown in a flat drawing. The distance perpendicular to the screen.
Threading Glossary
Angle of Thread
The angle between flanks.
External Thread
A thread formed on the external surface of a cylinder.
Flank
The straight sides that connect the crest and the root.
Major Diameter
The diameter of an imaginary cylinder that just touches the crests of an external thread or roots of an internal thread.
Minor Diameter
The diameter of an imaginary cylinder that just touches the roots of an external thread or crests of an internal thread. Also called Root Diameter.
Pitch (Threading)
The nominal distance between two thread roots or crests next to each other; or between the centers of other repetitive shapes.
Right-Hand Thread
The most common type of thread. It is a screw thread that is tightened by rotating clockwise when viewed from the head.
Rolled Thread
A thread formed by plastic deformation of a rod instead of cutting.
Shoulder Screw
A screw with an unthreaded portion used for more precise and secure locating. It can also be used as a bearing surface like in pulleys.
UNC/UNRC (Unified National Coarse)
A thread form with a 60 degree flank angle, rounded roots and flat crests. The unified thread is based on inch sizes and was first standardised in 1948. It is the most commonly used thread system used in the majority of screws, bolts, and nuts.
UNF/UNRF (Unified National Fine)
A thread form using a finer pitch than UNC. It is used when a higher tensile strength is needed than the coarse thread series, when smaller length of engagement is needed, when a thinner wall is available, or when instruments and parts require fine adjustments.
UNEF/UNREF (Unified National Extra-Fine)
A thread form using a finer pitch than UNF. It is used for the same reasons that UNF is used over UNC, but for more strict requirements.