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CNC Machining Glossary

In the world of modern manufacturing, CNC machining has revolutionized the way we produce complex parts with precision and efficiency. CNC (Computer Numerical Control) technology enables automated and precise control of machine tools, significantly improving the manufacturing process. As CNC machining continues to advance, it’s crucial for professionals in the industry to be familiar with essential terminology.

CNC Machining Center
CNC Machining Center
  1. Boring: A machining process used to enlarge or refine existing holes in a workpiece.
  2. CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing): Integrated software that facilitates designing and manufacturing processes.
  3. Chamfer: Beveled edge or corner created by machining to remove sharp edges.
  4. Chip: The small pieces of material that are removed from the workpiece during machining.
  5. Chuck: A device used to hold the workpiece or cutting tool securely in place on a machine.
  6. CNC (Computer Numerical Control): A method of controlling machine tools through pre-programmed instructions.
  7. Contouring: Machining along a specific path to create complex shapes and profiles.
  8. Counterbore: A cylindrical recess at the end of a hole, allowing the bolt head to sit flush with the surface.
  9. Countersink: A conical recess at the end of a hole, allowing the screw head to sit flush with the surface.
  10. Cutting Speed: The speed at which the cutting tool moves past the workpiece surface.
  11. Depth of Cut: The depth of the material removed by a single cut of the cutting tool.
  12. Drill Bit: A cutting tool used for creating holes in the workpiece.
  13. End Mill: A type of milling cutter with cutting edges on the bottom and sides.
  14. Face Milling: Machining the surface of a workpiece perpendicular to the spindle.
  15. Feed Rate: The speed at which the cutting tool moves through the material during machining.
  16. Fixture: A device used to hold the workpiece in place during machining.
  17. G-code: A language used to program CNC machines, providing instructions on tool movement and operation.
  18. Grinding: A process that uses abrasive wheels to remove material from the workpiece.
  19. Helix Angle: The angle at which the cutting edge of a tool is inclined concerning the axis of rotation.
  20. Honing: A finishing process that improves the surface texture and roundness of a hole.
  21. Jig: A device that holds the workpiece and guides the cutting tool during machining.
  22. Keyway: A slot or groove machined into a shaft to receive a key for coupling with other components.
  23. Lathe: A machine tool used for turning operations.
  24. Machining: The process of shaping, cutting, or removing material from a workpiece.
  25. Milling: A machining process that uses rotating cutting tools to remove material from the workpiece.
  26. Milling Cutter: A rotating cutting tool used in CNC milling.
  27. M-code: A subset of G-code that controls auxiliary functions such as tool changes or coolant activation.
  28. Offset: An adjustment made to the machine’s coordinate system to align the tool with the workpiece accurately.
  29. Parting: The process of cutting off a finished part from the rest of the workpiece.
  30. Peck Drilling: A drilling technique that involves periodically retracting the drill bit to clear chips during deep-hole drilling.
  31. Plunge Cut: A vertical cutting movement used in drilling and milling operations.
  32. Profile: The outline or cross-section of a part that needs to be machined.
  33. Punching: A process that uses a punch and die to create holes or shapes in sheet metal.
  34. Quenching: A heat treatment process that rapidly cools the workpiece to increase its hardness.
  35. Rapid Traverse: The high-speed movement of the cutting tool between machining operations.
  36. Reamer: A cutting tool used to improve the accuracy and finish of drilled holes.
  37. Roughing: The initial removal of material to prepare the workpiece for finishing operations.
  38. Shaping: A machining process that removes material by moving a tool along a straight path.
  39. Spindle: The rotating shaft that holds the cutting tool or workpiece in a machine.
  40. Spindle Speed: The rotational speed of the cutting tool or spindle, measured in RPM.
  41. Tapping: The process of creating threaded holes in a workpiece using a tap.
  42. Tolerance: The allowable variation in the dimensions of a machined part.
  43. Tool Holder: A device that holds the cutting tool securely in place during machining.
  44. Tool Nose Radius: The radius at the end of the cutting tool, affecting the finish and accuracy of machining.
  45. Toolpath: The specific route or trajectory that the cutting tool follows during machining.
  46. Toolpath Simulation: A virtual representation of the machining process to check for errors and collisions.
  47. Traverse Rate: The speed at which the cutting tool moves between machining operations.
  48. Turning: A machining process that rotates the workpiece while a cutting tool shapes it.
  49. V-block: A device used for holding round or cylindrical workpieces during machining.
  50. Vertical Machining Center (VMC): A CNC machine with a vertical spindle orientation.
  51. Waterjet Cutting: Using a high-pressure waterjet to cut materials, often combined with abrasive particles for added cutting power.
  52. Workholding: The methods and devices used to secure the workpiece during machining.
  53. Workpiece: The material being machined, often a metal or plastic part.
  54. Y-axis: One of the coordinate axes in a CNC machine, providing additional movement along the vertical plane.
  55. Z-axis: One of the coordinate axes in a CNC machine, providing vertical movement.
  56. 5-Axis Machining: CNC machining that allows simultaneous movement of the cutting tool in five axes for complex geometries.
  57. 6-Axis Machining: CNC machining with an additional rotational axis, providing greater flexibility for complex parts.
  58. 7-Axis Machining: CNC machining with even more axes, allowing for intricate and versatile operations.
  59. 8-Axis Machining: Advanced CNC machining with multiple rotational and linear axes for high-precision and complex components.
  60. 9-Axis Machining: State-of-the-art CNC machining with nine axes of movement, offering unparalleled versatility and accuracy.


Understanding the key terminology in CNC machining is vital for engineers and manufacturers striving to optimize production processes, enhance efficiency, and deliver high-quality products. This comprehensive glossary has covered essential terms that encompass various aspects of CNC machining, from basic concepts to advanced techniques. By incorporating this knowledge into your daily practices, you will be better equipped to excel in the dynamic and ever-evolving world of CNC machining.

As CNC technology continues to advance, it is essential to stay updated with the latest developments and innovations in the industry. By continuously expanding your knowledge and expertise, you will be at the forefront of modern manufacturing, pushing boundaries, and shaping the future of CNC machining. Embrace the power of CNC machining glossary terms, and let it empower you in your pursuit of precision engineering and manufacturing excellence.