Centreless grinding - Square becomes round

Concentrical glass sparts with a high surface quality

Centreless grinding – or rounding – is a high-quality, chipping manufacturing process for glass, ideally suited for parts that require high surface quality and closest machining tolerances. What began centuries ago as a handicraft art is an extraordinarily complex process today.

We encounter round glasses, for example, as transparent protective elements for lights or as sight glasses in the process industry. To turn square or roughly pre-aligned blanks into uniform, concentrical glass parts, we clamp them between the tips of a precision centreless grinding machine and bring them to the desired diameter. Tolerances as low as ± 0.001 with regard to dimensional accuracy, concentricity and cylindrical shape are achievable (in accordance with DIN EN ISO 286-1; surface roughness in accordance with DIN ISO 1302).