The most common type of glass cutter - roller. The high popularity is due to the low cost of such tools. But the possibilities are not rich - 350 m glass with a thickness of up to 5 mm. As a cutting element, a roller made of hard alloys is used. Usually used rollers of an alloy of tungsten and cobalt with a diameter of 6.6 mm and a sharpening angle of the cutting edge 100 °. The modest life of a glass-cutter is increased by adding additional rollers to the holder, which are installed in the working position within a minute. If before each cut we wet the cutting element with machine oil, then we can significantly improve the quality of the cut and increase the tool life. Blunt rollers are easy to sharpen with a fine-grained abrasive stone, having previously secured them in a holder of a screw and a hollow sleeve with internal thread.