Below you’ll find a few common terms for precision engineering projects

The team at PDQ Precision has many decades of experience working on highly accurate precision engineering projects. Below we explain some basic terminology to describe our tools and processes.

What is CNC milling?

CNC milling is an engineering process that uses rotating, cutting tools with multiple points to remove material from a workpiece. Milling machines can use horizontal or vertical machining centres and are used for wide range of applications including:

  • Cutting of internal and external threads
  • Create slots, holes and chamfers safety

What is CNC grinding?

CNC grinding uses a rotating wheel to cut material away from the workpiece. Through-feed grinding is a centreless grinding method and passes through the machine itself. In-feed is another form of centreless grinding where the wheel is moved around the workpiece.

  • Through-feed: for high volume grinding
  • In-feed: for precision grinding of complex shapes
  • Centreless: the workpiece is held between the grinding wheels

What does X, Y and Z axis mean?

CNC machines are often referred to as 3-axis or 4-axis machines.

  • X = Up and down on the left side
  • Y = Side to side on the right side, i.e. rotated horizontally 90° to the X axis
  • Z = Vertical, perpendicular to X or Y axis – represents depth
  • A = 4th axis, angles created by rotation of the workpiece

What is reverse engineering?

Reverse engineering is a method where obsolete or discontinued parts can be produced by measuring an old original part and copied using modern machines and methods.

  • Manufacture of no longer available parts.
  • CAD designs produced from old components.

What is the difference between generating and forming in engineering?

In engineering terms, ‘generating’ is where a cutter is driven around a path to produce a shape or profile. ‘Forming’ is producing a shape that is identical to the cutter that has been used to produce it.

  • A round drill forms a round hole.
  • A round milling cutter can generates a square profile.