Abstract: The invention relates to a process of providing a scratch-resistant coating for a lens made of an optical material comprising synthetics. In order for the synthetic material, for example a CR 39, to be protected against scratches, a very thin adhesion layer of SiO is applied first, and is subsequently provided with a thick SiO.sub.2 layer. Both layers are deposited in a vacuum chamber which comprises both a thermal vaporizer for vaporizing the coating materials and a plasma source for irradiating the substrate simultaneously with application of the vaporized coating material.

Abstract: A device which includes an elongated rod made of a metal having a generally silver color and having a threaded end and a component having an internal thread which engages the end of the rod. The threaded end portion has a borderline where a region coated with titanium nitride borders an uncoated region of the rod.

Abstract: A process for the preparation of shaped bodies includes preparing a plastic mixture of a material selected from the group consisting of aluminum oxides, aluminum hydroxides, silicon oxides, silicon hydroxides and mixtures thereof from a predominantly dry component K1 in powdered form and a paste component K2 comprising water and additional additives, continuously extruding the plastic mixture into cut lengths, shaping the cut lengths into spherical shaped bodies and drying the spherical shaped bodies and optionally tempering such bodies to form catalyst and catalyst supports. The solids content of the powdered component K1 is from 65 to 100% by weight whereas the solids content of the paste component K2 is 10 to 50% by weight. Preferable spherical shaped bodies are based on Al.sub.2 O.sub.3, SiO.sub.2, or Al.sub.2 O.sub.3 /SiO.sub.2.