•  
• Bearing Type
• Current code
  638/4-2Z
• The inside diameter of
• d
  4
• Outer diameter
• D
  9
• Thickness
• B
  4
• Basic dynamic load rating
• Cr
  0.54
• Basic static load rating
• C₀
  0.18
• Fatigue load
• P_u
  0.07
• Reference speed
• Reference speed
  140000
• Limit speed
• Limit speed
  70000r/min
• Type
• Type
  Deep groove ball bearings

638/4-2ZBearings are suitable for gearboxes, instruments, motors, household appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction machinery, construction machinery, roller skates, yoyos, etc.