Abstract: A tool head capable of introducing deep recesses into hard and brittle material such as glass and glass ceramics is provided. The tool head includes a hollow cylindrical abrasive body merging into a hollow shank. The hollow cylindrical abrasive body has an end face with a central abrasive area at the location of a cylinder axis. The central abrasive area is connected with the inner wall surface of the hollow cylindrical abrasive body by at least one web. The end face of the abrasive body, the web, and at least a portion of the outer wall surface of the abrasive body are covered with abrasive. The hollow shank has at least one opening to the interior between the at least one web and the inner wall surface of the abrasive body.

Abstract: A mirror, a mirror substrate, a method for producing are provided. The mirror substrate is made of a material having a coefficient of mean linear thermal expansion of less than or equal to 1*10?6/K. The mirror substrate includes at least one feature selected from a group consisting of: a ratio of a lateral dimension to a maximum thickness of at least 100, a ratio of the lateral dimension to the maximum thickness of at least 150, a ratio of the lateral dimension to the maximum thickness of at least 200, a ratio of the lateral dimension to the maximum thickness of at least 300, a weight per unit area of 100 kg/m2 or less, a weight per unit area of 50 kg/m2 or less, a weight per unit area of 30 kg/m2 or less, a weight per unit area of 15 kg/m2 or less, a mirror surface with a roughness (Ra) of at most 3.5 ?m, and a mirror surface with a roughness (Ra) of less than 1.2 ?m.

Abstract: An assembly is provided that includes a mineral-based monolithic support for full-surface supporting of a workpiece during processing and transportation and a workpiece supported thereon, wherein the surface of the support is designed so that adherence of the supported workpiece is prevented, and wherein the support has provisions with means inserted therein, which permit to lift the workpiece from the support from below and/or to shift the workpiece laterally, and furthermore relates to a mineral-based monolithic support suitable for this purpose.

Abstract: An assembly is provided that includes a mineral-based monolithic support for full-surface supporting of a workpiece during processing and transportation and a workpiece supported thereon, wherein the surface of the support is designed so that adherence of the supported workpiece is prevented, and wherein the support has provisions with means inserted therein, which permit to lift the workpiece from the support from below and/or to shift the workpiece laterally, and furthermore relates to a mineral-based monolithic support suitable for this purpose.

Abstract: A tool head capable of introducing deep recesses into hard and brittle material such as glass and glass ceramics is provided. The tool head includes a hollow cylindrical abrasive body merging into a hollow shank. The hollow cylindrical abrasive body has an end face with a central abrasive area at the location of a cylinder axis. The central abrasive area is connected with the inner wall surface of the hollow cylindrical abrasive body by at least one web. The end face of the abrasive body, the web, and at least a portion of the outer wall surface of the abrasive body are covered with abrasive. The hollow shank has at least one opening to the interior between the at least one web and the inner wall surface of the abrasive body.