How do you cut a hole in glass?
– Place the point of the drill at the center of the marked point on the glass.
– Pour a few drops of lubricating oil on the area around the drill tip and glass.
– Beginning at low speed with medium pressure, drill a small starter hole into the glass.
You can only cut/drill holes in glass BEFORE tempering. Re: How to cut through glass patio table top? also – if anybody out there does have a table with an umbrella, make sure to use the plastic/rubber insert ring for the hole, or you will eventually end up finding out what broken tempered glass looks like.