1. Appearance discrimination

 

(1) See if there are obvious oil stains. In order to prevent bearing rust in the process of transportation and use, manufacturers generally carry out anti-rust treatment on its surface when producing bearings. Some factories have good anti-rust treatment technology, and some factories have poor anti-rust treatment technology. And the surface of the parts produced by this technology is no obvious oil stains.

 

(2) look at the luminosity and color. If light with surface observation of thin wall bearing quality, really good quality of the surface of the thin wall bearing should be in color with a raven, the cause of this raven color whether the steel is thin wall bearing use standard and cutting fluid used in the grinding process and its mutual effects, such as the effect of colour and lustre of the previous two pure to give priority to.

 

(3) See if the chamfering is even. This chamfer is the junction between two different faces of the part. For those parts of poor quality, their chamfering treatment is not quite uniform. In addition, in order to increase the hardness of thin-wall bearings, the chamfering of thin-wall bearings after quenching and other heat treatment is black, which will make many people mistakenly think that it is caused by incomplete processing. In fact, it is not, which just reflects the processing method of thin-wall bearings.

 

2. Sound discrimination

 

When judging the quality of bearings, we need to hold this part and let its coat run in a small range. Also, as the coat rotates, we should listen carefully to see if there is any noise from this part. If the part is noisy or does not work well, the quality of the part is not good enough.

 

3, test discrimination

 

(1) Rotation. When rotating bearings, good bearings turn smoothly and smoothly, while defective ones, rotation will feel foreign body inside, not smooth.

 

(2) weighing. Good bearings and counterfeits are also different in weight. Because counterfeits use different materials, they will be light in weight and have a lot of difference in price.