SIC SUPER SMOOTHNESS,LOW FRICTION

 The SiC ring is diamond-polished. Since the hard and durable SiC is polished drastically and smoothly by special procedure, the surface is very smooth even though you check it by microscope. The 20 times or more of the line endurance was recorded by outstanding low abrasion resistance when testing the line-slide experiment to compare it with the hard ring (Fuji experiment). The line damage remarkably decreased and the color does not change or rust, neither.