Roll bodies in the nature of roller bearings for machines, namely, balls, rollers, cylinders, cones and pins made of steel, in particular stainless steel, of ceramics, in particular made of silicon nitride, zircon oxide or silicon carbide or of glass; machine parts, namely, brass balls for bearings; machine parts, namely, bearing housings made of steel, gray cast iron, brass, plastics, in particular polyamide; machine parts, namely, rolling bearings and parts thereof as well as accessories th...