1. Unqualified Rotary Strength

Rotary strength is an important index in the manufacture and use of grinding wheels. Defects that are dangerous or unsafe to users or equipment of products with unqualified rotational strength are classified as “fatal defects”. The rotational strength of fast working grinding wheels in random inspection must be all qualified. If one piece is not qualified, the batch will be judged to be unqualified.

2. Unqualified static balance

Static balance refers to the vibration caused by the mismatch between the center of mass and the center of rotation when the fast working grinding wheel rotates. There are several kinds of harms caused by unbalanced grinding wheel:

• A. Vibration caused by unbalancing accelerates wear of grinding machine spindle.
• B. The center of gravity of the grinding wheel does not coincide with the axis of rotation, which will cause vibration when rotating at high speed, which will affect the quality of processing and the accuracy of machine tools, and even cause machine damage and grinding wheel fragmentation in serious cases.
• C. The surface of the processed workpiece is prone to vibration, and the processing accuracy and surface roughness become worse.
• D. The uneven wear of grinding wheel affects the uniformity of self-sharpening of grinding wheel.
• E. The unqualified static balance seriously reduces the performance of the product, which has a serious impact on the performance of the processed parts, and is classified as “heavy defects”.

3. Unqualified Hardness

The hardness of the fast working grinding wheel reflects the grinding performance and is one of the important indexes to measure the quality of the grinding wheel. The grinding quality is affected by the hardness, while the service life of the grinding wheel is short due to the softness.

4. Unqualified end and radial runout

Unqualified end runout and radial runout will cause the wheel to sway and affect the balance performance, which should be controlled within the allowable range.