Selection and Assessment of Vibration Grades (Z1/Z2/Z3) for Deep Groove Ball Bearings

When purchasing and inspecting bearings, many people focus on dimensional tolerances and load ratings ，but overlook one thing which will  directly affects equipment performance: the vibration grade.

In fact, the vibration grade not only determines the noise level during operation but also reflects the machining precision of the raceways and assembly quality, Learning about vibration grades is liking to reading a bearing's "health check report."

What Do Z1, Z2, and Z3 Actually Represent?

According to the JB/T 7047-2006 standard, vibration limits for deep groove ball bearings are categorized into three grades: Z1, Z2, and Z3. The higher grade means stricter vibration limits.And quieter, smoother bearing operation.

Measurement Methods and Key Process Requirements

Bearing vibration measurement adheres to two industry standards: JB/T 5314 (acceleration method, suitable for high-frequency defect detection) and JB/T 5313 (velocity method, suitable for overall vibration assessment).

Selection

Choose Z2 for standard operating conditions, Z3 for precision equipment, and Z1 for normal ,general-purpose applications.

A vibration grade may just look like a letter and a number on a report, but it actually contents all the information and manufacturing process across the bearing production:from grinding and super-finishing to final assembly.

Selecting the right vibration grade is not just about choosing quiet operation; it is about ensuring reliability and stable quality.