Accoring to related standard,the vibration noise(dB) of beafings for their vibration under acceleration are divided into four groups:Z1,Z2,Z3 and Z4.Also they can be divided into four groups in according to vibration speed(um/s):V1,V2,V3,and V4.
      Ussally,bearings are delivered with Z1 group vibration value if no special requiement from customers,while the bearings for export will be delivered with vibration Z2 group specification.However,please note your special requirement on vibration in your order.
      Single bearing vibration noise under acceleration(dB)specification is shoewn on table A.
      Single bearing vibration speed(um/s)specificatin is shown on table B.