Counter Gear Ceramic Bearing Kit (4x9x4)

Trex 500/Trex 600 Counter Gear Ceramic Bearing Kit 2pcs (4x9x4) 684ZZCRM

High Quality CERAMIC bearings

Replace stock bearings by these highest quality CERAMIC bearings with much higher tolerance and smoothness and feel a much difference in response.

Specifications:

• 2 x Bearings 684ZZCRM (4x9x4mm)
• Quantity: 2 pieces
• Used for Trex 500/Trex 600 Counter Gear

Ceramic Materials, which can be used in making bearings,  includes mainly Silicon Nitride(Si3N4),  Zirconia(ZrO2), Alumina(Al2O3) and so on. They are noted for their characters high strength in high rigidity,good wearability; high temperature, corrosion resistance;  high resistance,  non-magnetic,  electrical insulation,  these characters quality them for replacing steel to make bearings  to meet the requirements in a severe condition, where a steel bearing
cannot withstand.

Hybrid ceramic bearing features bearing rings made of bearing steel(Gcr15) or stainless steel(9cr18).  The ceramic balls is mainly made of Silicon Nitride,  Zirconia or  Alumina,  among which Silicon Nitride is  of excellent overall performance and has become the preferred material for ceramic ball bearing.

The density of Silicon Nitride is 3.20g/cm3, much lower than  that of bearing steel(7.85g/cm3).  For this reason, the ceramic rolling element  can effectively restrain  the centrifugal force  generated  by the high-speed rotation and reduce the load of rolling element.

Meanwhile, it can reduce the rotational slide between the rolling element and the raceway surface, and thus prevent surface damage.  Therefore, ceramic ball bearing is the best choice for high-speed rotation application, such as high-speed motor spindle bearing, machine spindle bearing, dental drill bearing,  instrument bearing and hard drive bearing, high-speed wheelhead bearing.  It can also be used in the civilian products like roller skates, aero-modellings and electric toys.