the HTB-31 bearing breaks through the limit of general bearing whose lubrication depends on oil film.So it is suitable for high temperature,heavy duty,anti-corrosion or where oil is hard to be introduced.It performance doubles both on hardness and wear-friction.It is now widely applied in successive casting machines,steel rollers in metallography,mineral machine,ships,steam turbine,hydraulic turbines and injection molding machines for plastics.