Micro-hardness of its coating is obviously higher than that of normal steel ring. It endows with high abrasion and long service life, can reduce the producing cost.

It can obviously shorten the running-in period of coated ring, reduce the yam feather, improve the quality of yam to assure its normally used.

The surface of coated ring is very smooth after being further-polished.

It endows high anti-rust performance, can adapt high-temperature and high-moist environment.