DRILL PIPE…

When I need to drill a hole in glass, I use this way. In the Chuck of the drilling machine is clamped copper tube length of 100 mm (the diameter is adjusted depending on what you need the hole). Tube pre-filled with a mixture of any mineral oil with dust, corundum, emery. When drilling rate (500-1000 rpm) periodically raise the tool over the glass to the mixture was slowly flowed under the “drill”. Feeding — with minimal effort, otherwise the glass will burst. If it is thick or multilayered, it is .you can, occasionally lifting the cartridge with a tube, carefully chipped resulting in the center hole of the glass cylinder.