How to judge the quality of flap wheel?

Flap discs are products that are often used in life. It is of great help to industrial production and construction. Has high tensile, impact and flexural strength. So how do we distinguish the quality of the flap wheel when we buy it?
Check the nameplate and instruction manual of the flap disc. The nameplate parameters should be consistent with those on the 3C certificate.
Observe the outer packaging of the flap wheel flap disc. The outer packaging should have clear patterns and no damage. Open the box to observe the appearance of the flap wheel flap disc. The color should be uniform, and there should be no obvious shadows and dents on the surface of the plastic parts. There should be no scratches or bumps. The aluminum casting coating is smooth and beautiful without defects. The surface of the whole machine should be free of oil and stains.
Hold the wheel cut-off disc by hand. Turn on the power and frequently operate the switch by hand. Start the tool frequently and observe whether the on-off function of the stone cutting machine switch is reliable.
During the trial operation of flap wheel flap discs. At the same time, observe whether there are any abnormal phenomena in the TV and fluorescent lamps on site. in order to confirm whether the tool is equipped with a radio interference suppressor.
Observe the reversing sparks during the trial operation of the flap wheel flap disc. Its reversing spark should not exceed level 3/2. Generally look in from the air inlet of the tool. There should be no obvious arcing on the surface of the commutator. During operation, there should be no abnormal noise.
The above is an introduction to the method of judging the quality of the flap wheel flap disc. Hope you all understand!