1[LOW FRICTION] These ball bearings rotate with minimal frictional resistance and can achieve high accuracy and stable motion. 2[GLOSSY SURFACE] The bearing surface is glossy and flat, waterproof and dustproof, not easy to rust, and has a long service life. 3[EXCELLENT MATERIAL] High carbon chromium bearing steel material, with high hardness, good toughness, wear resistance and contact fatigue strength. 4[LOW NOISE] With fine processing, working in coordination with the machine, greatly improving the efficiency of the machine with low noise. 5[MULTIPLE USAGES] Widely used in gearboxes, motors, household appliances, internal combustion engines, transportation vehicles, roller skates, etc.Item Type: Ball Bearing Kit_x000D_Material: High Carbon Chromium Bearing Steel_x000D_Application: Widely used in gearboxes, instrumentation, motors, household appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction machinery, engineering machinery, roller skates, etc._x000D_Product Parameter Specifications:_x000D_ModelInner DiameterOuter DiameterThickness_x000D_120420mm / 0.8in47mm / 1.9in14mm / 0.55in_x000D_120525mm / 1in52mm / 2in15mm / 0.59in_x000D_120630mm / 1.2in62mm / 2.4in16mm / 0.63in_x000D_120735mm / 1.4in72mm / 2.8in17mm / 0.67in_x000D_120840mm / 1.6in80mm / 3.1in18mm / 0.71in4 x Ball BearingsPlease pay attention to match the corresponding size before use.