Why to use pilot pins with annular core cutters?

The ejector pin or also called as the pilot pin has 3 major functions:

  1. Centering: The ejector pin helps to position the drilling machine and drilling tool to take the center of the hole. Once the tip of pilot pin matches the center mark made on the material to be drilled, its considered that the cutting tool is now centered correctly.
  2. Oiling: The ejector pin while drilling is pushed up inside the machine arbor, which activates the flow of coolant (lubricant) from inside the annular cutter. By means of the automatic internal lubrication, cutting oil is supplied via the ejector pin to the annular cutter in just the right quantity.
  3. Ejecting: In the final stage, the ejector pin, pre-stressed by means of a spring, pushes the core out of the drill hole.

Use of ejector pin

Image copyrights: BDS Maschinen GmbH (Germany)