The world of CNC automatic lathes is full of technical terms.
This glossary explains the words beginners most often stumble over, one at a time, each on its own illustrated page.
Click any term to see its definition, diagram, and related articles.
Below you will find two ways to browse: by category and alphabetically.
Terms are added over time (currently 31).
In This Article
Browse by Category
① Machine Structure & Types
- CNC (Computer Numerical Control)Controlling a machine tool numerically by computer
- SpindleThe heart of the lathe, which grips and rotates the material
- Back Spindle (Sub-Spindle)A second spindle that machines the reverse side of the part
- Guide BushingThe bearing on a Swiss-type that supports the bar near the cutting edge
- Tool PostThe mount that carries the cutting tools
- Bar Feeder (Material Feeding Device)The device that feeds bar stock automatically
- Swiss-Type (Sliding Headstock)A design with a sliding spindle for high-precision slender parts
- Fixed HeadstockA design in which the spindle stays put while machining
- Gang Type (Gang Tooling)Tools in a row for high-speed changes
- Turret TypeMany tools indexed by rotation
- NC LatheA lathe that grips and machines one workpiece at a time
② Machining Terms
- TurningMachining by rotating the material against a tool
- WorkpieceThe material or part being machined
- Cutting Tool / InsertThe tool that cuts the material and its replaceable tip
- Nose RadiusThe rounding at the tip of a cutting tool
- Built-Up EdgeCut material welding itself onto the cutting edge
- Oscillation CuttingVibrating the tool to break up chips
- Parting (Cut-Off)Separating the part from the bar stock
- ThreadingMachining a thread form
- BurrAn unwanted protrusion left on an edge by machining
③ Cutting Conditions
- Cutting Speed (Surface Speed)How fast the cutting edge travels over the material surface
- FeedHow far the tool advances per revolution
- Depth of CutThe depth of material removed in one pass
- Constant Surface Speed ControlAn NC function that keeps cutting speed constant as the diameter changes
④ Precision & Quality
- RoundnessHow closely a cross-section matches a perfect circle
- Surface RoughnessA measure of how smooth a machined surface is
- In-Machine MeasurementMeasuring inside the machine and compensating automatically
- ToleranceThe permitted range of a dimension
⑤ Materials & Operation
- Difficult-to-Cut MaterialsMaterials that are hard to machine (stainless steel, etc.)
- SetupPreparation work before machining
- Unattended OperationContinuous volume production with nobody standing by
Browse Alphabetically
B Back Spindle / Bar Feeder / Built-Up Edge / Burr
C CNC / Constant Surface Speed Control / Cutting Speed / Cutting Tool / Insert
D Depth of Cut / Difficult-to-Cut Materials
F Feed / Fixed Headstock
N NC Lathe / Nose Radius
S Setup / Spindle / Surface Roughness / Swiss-Type
T Threading / Tolerance / Tool Post / Turning / Turret Type
About This Glossary
This glossary exists to answer the beginner's question "what does this word mean?" one term at a time, with diagrams, and it is expanded continually.
Each term page also links to more detailed articles.
See also the Getting Started with Automatic Lathes and Basics categories.