Glossary of CNC Terms

Whether you’re a beginner or a seasoned professional, this guide will help you understand the key terms and concepts in CNC machining.

A

  • Axis
    Refers to the directions in which a CNC machine can move. Common setups include 3-axis, 4-axis, and 5-axis machines, which allow for movement along X, Y, Z, and rotational planes.
  • Adaptive Clearing
    A CAM strategy designed for efficient material removal while minimizing tool wear.
  • Automation
    The use of computer systems to operate CNC machines with minimal human intervention.

B

  • Ball Screw
    A precision mechanism that converts rotational motion into linear motion, commonly used to move CNC machine axes.
  • Bed
    The base structure of a CNC machine that supports the workpiece and machining components.
  • Bit
    A cutting tool used in CNC machining, often referred to as an end mill or drill bit.

C

  • CAD (Computer-Aided Design)
    Software used to create precise 2D or 3D designs for CNC machining.
  • CAM (Computer-Aided Manufacturing)
    Software used to convert CAD designs into machine instructions (G-code).
  • Chip Load
    The thickness of material removed by a single cutting edge of the tool during machining.
  • Controller
    The computer or electronic device that interprets G-code and sends commands to the CNC machine.

D

  • Depth of Cut
    The amount of material removed in one pass of the cutting tool.
  • Drill Press
    A machine used for drilling holes in materials, often included in CNC operations.
  • Dynamic Milling
    An advanced milling technique designed to optimize tool paths and improve material removal rates.

E

  • End Mill
    A type of cutting tool used in CNC milling to remove material from a workpiece.
  • Engraving
    A process of cutting or carving designs into a material surface using a CNC machine.
  • Extrusion
    The process of shaping material by forcing it through a die, often used in conjunction with CNC machining.

F

  • Feed Rate
    The speed at which the cutting tool moves through the material, measured in inches per minute (IPM) or millimeters per minute (mm/min).
  • Fixture
    A device used to hold a workpiece in place during machining.
  • Flute
    The grooves on a cutting tool that allow chips to escape during machining.

G

  • G-Code
    The programming language used to control CNC machines, specifying movements, speeds, and tool actions.
  • Grain Direction
    The orientation of fibers in materials like wood, which affects machining quality.
  • Grooving
    A machining operation that creates narrow cuts or channels in a workpiece.

H

  • High-Speed Machining (HSM)
    A machining technique that uses increased speeds and lower depths of cut for faster production.
  • Hybrid Machine
    A CNC machine that combines additive and subtractive manufacturing techniques.

I

  • Interpolation
    The process of generating smooth curves or movements in CNC machining, such as circular interpolation.
  • IoT (Internet of Things)
    The integration of smart technology and data sharing in CNC operations.

L

  • Lead Screw
    A screw mechanism that drives the movement of CNC machine axes.
  • Linear Motion
    Straight-line movement along an axis, controlled by ball screws or guide rails.
  • Lubrication
    Essential for reducing friction and extending the lifespan of CNC components.

M

  • M-Code
    Machine control codes used in CNC programming to manage auxiliary functions like coolant or spindle on/off.
  • Mill
    A CNC machine that performs milling operations to remove material and shape the workpiece.
  • Multi-Axis Machining
    CNC operations involving more than three axes for greater flexibility and complexity.

P

  • Parametric Programming
    A programming technique that uses variables to create flexible and reusable CNC programs.
  • Plunge Rate
    The speed at which a cutting tool enters the material.
  • Post-Processor
    Software that translates CAM output into G-code tailored for a specific CNC machine.

R

  • Rapid Traverse
    The fast movement of the machine’s axes when not cutting, to save time between operations.
  • RPM (Revolutions Per Minute)
    The speed at which the spindle rotates the cutting tool.
  • Router
    A type of CNC machine designed for cutting softer materials like wood or plastics.

S

  • Spindle
    The rotating component of a CNC machine that holds the cutting tool.
  • Surface Finish
    The texture and quality of a machined surface, often specified in micrometers or microinches.

T

  • Toolpath
    The route the cutting tool follows to machine the workpiece.
  • Tool Wear
    The gradual degradation of a cutting tool during machining.
  • Tolerance
    The allowable deviation from a specified dimension in machining.

W

  • Workholding
    Techniques or devices used to secure a workpiece during machining.
  • Workpiece
    The material being machined in a CNC operation.

Z

  • Z-Axis
    The vertical axis in a CNC machine, controlling up-and-down movement.

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