2.1 Materials for bearing rings and rollers
Our company adopts high qualified GCr15 vacuum degassing bearing steel for rings. The steel has gone through vacuum smelting, which greatly reduces the oxygen and other inclusions. After special heat treatments, the rings can withstand huge contact stress and alternating stress, which will greatly extend the life span of the bearings. The steel has such performances as:
◆ high solidity
◆ high wear-resistance
◆ high contact fatigue strength
◆ certain impact toughness and fracture toughness
◆ good size stability
◆ good rust-proof performance
We can select 20CrMo for the shaft bearing axis in accordance with our customers' demands, which will turn into hard-surface and soft-core after carburizing treatments. Thus, the axis has better crack resistance toughness.
The steel code and its application scope are as follows:

China	Japan	Germany	United States			Application Scope
GB	JIS	VDEh	ASTM	AISI	SAE
GCr15	SUJ2	100Cr6	E52100	52100	52100	The inner and outer rings of the bearing, rollers
20CrMo	SCM420	25CrMo4				Water axis bearings (selective)

2.2 Materials of the bearing roller cage and the seal ring
The inner cage of the bearing adopts reinforced engineering plastic GRPA66 and the seal ring uses dustproof and lipid leakage tested low-carbon steel board stamping frame + NBR contact seal. We can adopt expensive high-temperature and corrosion resistant FPM according to the customers' demands.
2.3 The oil filled in the bearing
Generally, it is special high-temperature resistant and antioxidant RONEX MP. We can use the oil ordered by the customers. RONEX MP Oil has the following performances:
◆　composite lithium multi-purpose oil, consistence rank: 2
◆　excellent high/low-temperature performances, applicable temperature range is: -40℃-165℃
◆　abrasion resistance and extreme pressure load during shock or heavy load.