How to identify the quality of bearings

Bearings are crucial foundational components in a wide variety of mechanical equipment, playing a decisive role in determining the precision, performance, service life, and reliability of machinery. Therefore, bearings must possess excellent quality and performance. At present, the quality of bearings available on the market varies widely, making it easy to purchase counterfeit products that often fail prematurely during use. Below, we’ll discuss how to identify the quality of bearings when making a purchase.

1. Is the typing clear?

Bearings manufactured by reputable producers all have their brand names, model numbers, and other information engraved on the surface. Although the characters are small, they are precisely stamped using steel-pressing technology—and the engraving is done before any heat treatment takes place. As a result, each character leaves an extremely deep indentation with remarkably clear markings. In contrast, counterfeit or substandard bearing products not only feature blurry lettering but also have markings that sit merely on the surface and can be easily wiped off. The stamping technique used on these fake bearings is extremely crude, and there are obvious signs of manual craftsmanship.

2. Is the surface smooth?

Bearing grinding is a critical process that requires selecting the appropriate grinding wheel to ensure proper grinding and strictly controlling the linear velocity to prevent raceway burn. After rough grinding, fine grinding should be carried out using resin-bonded grinding wheels with a grit size of either 46° or 60°. The grinding allowance must not exceed that used in rough grinding, and the surface finish must meet the specified quality standards. In contrast, some counterfeit or substandard bearing manufacturers lack specialized equipment, resulting in uneven bearing surfaces and numerous scratches.

3. Are there any cracks?

In the manufacturing process of bearings, multiple procedures are required, and during bearing machining, the components often need to be transferred several times. Throughout these processes, bearing fractures can occur. Such bearings have a very short service life and significantly compromise operational safety. By contrast, genuine bearings undergo 100% magnetic or radiographic inspection of their component parts before leaving the factory.