Manufacture -

Rounding

Rounding is the process of manufacturing glass disks which are used in level gauges, oil windows and apertures; generally, they fit in every circular hole. The most important qualities include precision, resistance to thermal and mechanical shocks and, naturally, the price. Original way of glass cutting which we use enables it to achieve high level of accuracy and resistance for a reasonable price.

When the glass is subjected to stress, it breaks in its thinnest spot. This is being used for dividing glass into several parts. Glass is disrupted in the cutting section and breaks exactly in this line when being bended. In this way you can break various shapes out of glass, even a disk. Unfortunately, this kind of production may cause small cracks along the edge of the fracture which appear more frequently. Glass is therefore more fragile and can break easily. Glass breaking is used mainly for the disks with big diameters. The smaller the diameter is, the more difficult it is to break the disk out of glass. You can have your disk made with this method in ordinary glazier's. Precision is approximately in millimeters.

We use glass rounding method. In other words, we gradually grind off layers of glass until it is not precisely round. Precision when using this method is approximately in hundreds of millimeters. The edges of the fracture are clean which increases mechanical and thermal resistance.


Detail of the edge
after glass breaking

Detail of the edge
after rounding

Direct comparsion of
both methods

Grinding can be performed in accordance with the two groups of cleanness.

Ordinary
Small scratches and spots can be found in the glass. It is sufficient for oil windows and other similar things. Fast and cheap production.
Optical
Scratches and spots are unacceptable. Demanding and quite expensive production. Suitable for optical apparatus.

Applications which lay stress on the resistance have to have also a facet on each of the edges. It is also possible to strenghten glass chemically.