The ceramic eyelet(ceramic ring) is the most commonly used component for the wire passing, and it is used in the wire passing position of the coil winding machine and the textile machinery. Normally it is used for less demanding occasions. The shape, finish and the hardness of materials must be improved in order to reduce the friction because of the wire sliding in the surface of the ceramic rings. According to the requirements, the Polish degree of porcelain eye can be regarded as roughness polishing, precision polishing and ultra-precision polishing. Features: 1. The inside surface Polish degree: Ra0.2~0.8. 2. The material: 99% AI2O3 with density of 3.85. 3. The hardness: HRa88.