Glossary of Terms Used in Machining
Bed or Bedplate
A flat surface used as the basic datum in a CNC machine
Blind hole
A hole in any component or part that does not pass all the way through it
Broach
A special tool for making a hole in a component which is not round, the process known as broaching
CAD
Computer Aided Design: a process whereby components are designed as 3D models on a computer, giving files which can be imported to a machining centre to make parts
CNC
Computer Numerical Control: the process whereby a computer digitally guides the movement of machine tools
Collet
A work holding chuck that centres round bar when tightened
Cutting Speed
The surface speed of the workpiece in a lathe or machining centre
Machining Centre
A machining centre is a modern machine which will perform all operations such as milling, boring, tapping, turning and drilling. Modern machines have sophisticated programming capabilities
Milling
A process where a part is machined using a rotary cutter which advances into the work piece to be machined. Direction, speed and pressure may be varied
Tap
A tool which cuts threads on the inside of a suitably sized hole
Turned Parts
Turning is a machining process in which a cutting tool describes a helix toolpath by moving linearly while the workpiece rotates. This refers to external surfaces. When a similar process is applied to internal surfaces, it is named 'boring'.