The first thing to infer is whether the outer packaging […]
The first thing to infer is whether the outer packaging of the oil-free bearing is clear: that is, whether the packaging of the self-smooth steel sleeve is clearly marked. Under normal circumstances, the brand of the oil-free and oil-free bearing factory has its own special design staff to design the outer packaging. If you look carefully, you should be able to identify and go out, and place a factory that has passed the manufacturing conditions for manufacturing. Therefore, the packaging is quite clear from the lines to the color blocks and is completely unmixed.
Then listen to whether there is any noise in the oil-free bearing, hold the inner sleeve of the oil-free bearing, turn the outer sleeve to make it rotate, and listen to whether there is any noise. This is a big difference from the standard manufacturer's brand that manufactures oil-free bearings and uses mechanical controls. Most of the counterfeit products are under the manufacturing conditions and are completely controlled in a hand-crafted workshop. During the manufacturing process, sand and other impurities will inevitably be mixed into the oil-free bearing body, so noises will be generated during the rotation. The next step is to see if there are dirty oil stains on the surface, and pay special attention when buying oil-free bearings.
At present, China’s anti-rust technology is not yet mature, so it is easy to leave thick oil traces when the oil-free bearing body is rust-proofed. However, there are almost no traces of anti-rust oil on the imported oil-free bearings. If you are an expert, you can smell the anti-rust oil by smelling the smell of oil-free bearings, but you can't see it. Then check whether the chamfer is even, that is, the junction of the horizontal plane and the vertical plane. Due to the limitation of manufacturing technology and no high-tech equipment, the counterfeit oil-free bearing will be handled poorly at these corners and corners. It is not difficult to see if you look closely.
Next, it is necessary to check whether the steel printing is clear, and the brand words, labels, etc. will be printed on the oil-free bearing body. The font is quite small, but most of the products produced by the factory use stencil printing technology, and the characters are pressed before the heat treatment. Therefore, although the font is small, it is concave-deep and quite clear. If it is a counterfeit product, its font is quite vague, because the printing technique is rough and the font floats on the surface, some can even be easily wiped off with a damp cloth or hand.