It is the process of drilling glass with drill bits of various diameters, with or without countersink.
Technical Information About Hole Standards is especially important for perforated glass sheets that will be subjected to the tempering process.

 

Technical Information About Hole Standards
The diameter of the holes should generally not be smaller than the thickness of the glass.
For smaller holes, the company that will drill the glass should be consulted.

Generally; The limitation of the hole positions relative to the edges of the glass sheet, the corners of the sheet and each other depends on the customer's request.