First, the characteristics of counterfeit bearings
1. The appearance is basically the same as the original, but its bearing capacity and limit speed are not consistent with the purpose.
2. In order to reduce the manufacturing cost, there is no requirement for precision.
3. In order to reduce the price, poor quality bearing steel materials are used.
4. The packaging and transportation handling methods are not standardized, which has adverse effects on the accuracy of bearing products.
Two, the impact of counterfeit bearings
1. Short service life.Bearings will be damaged in advance in use, which directly increases the enterprise budget and causes economic losses.
2, counterfeit bearings are easy to lead to dangerous accidents.The high damage of counterfeit bearings makes the machinery suddenly turn abnormally, stop suddenly or heat up and catch fire.
3. Disturbance of the relationship between procurement and distribution in the bearing market.In the face of interests, destroy the credibility between each other, resulting in bearing manufacturers have difficulty distinguishing and users do not trust.
Three, bearings mainly exist 8 kinds of fraud means
1, with iron, carbon steel manufacturing bearings (hardness is not enough) and repair scrap bearings (accuracy is not enough).
2. Label inferior bearings and bearings from small factories with the trademarks of big factories, and fake the internal and external packaging and certificate of qualification of products from famous big factories.
3, fake famous big factory users, dealers, agents, and even fake manufacturers spot sales department.
4. Use defective bearings to pass off as genuine bearings.
5, the ordinary bearings as high precision bearings.
Good goods mixed with fake goods.
Fake goods sell genuine prices, genuine goods sell high prices, use fake prices.
Cheap to fake, good quality to the real thing.
Four, the bearing brand on the market examples
1. Famous foreign bearing brands: SKF of Sweden, NSK of Japan, Timken of the United States, etc.;
2. Well-known domestic bearing brands: Luoyang bearing, Wafangdian bearing, Harbin bearing, etc.
There is no absolute good or bad point for bearings. It mainly depends on how you use them and where they are used. There are also NACHI, Tianma TMB, Renmo C&U, NXZ, Qian Chao QC, IKO, TG, ZYS, ZXY, NRB bearings and other brands of bearings.
Five, distinguish the skills of true and false bearings
1. Outer packing and certificate of qualification
A Whether the outer packaging is clear: under normal circumstances, the factory brand has its own special designer to design the external packaging, and arrange the factory with good production conditions for production, so the packaging from lines to color blocks are very clear, no ambiguity.
B Whether the certificate is standard:
● Authinal tile shop production of bearing certificate in the watermark, watermark inside the "ZWZ", and counterfeit certificate there is no such mark.
The certificate of Luoyang bearing has an anti-counterfeiting identification number, which can be inquired by telephone.
● Japan NSK no certificate of qualification, certificate this winter is unique to our country.
2, steel printing words
A Brand words and labels will be printed on the bearing body.
B domestic steel printing font is very small, most of the factory produced using laser etching, and in the bearing without overheating treatment before the word, so although the font is small, but deep concave, very clear.And fake products fonts not only blurred because of the rough printing technology, fonts floating on the surface, some can even be easily erased by hand.
C The steel mark on Japanese NSK is not tactile if you touch it by hand, but you can feel the presence of the steel mark by gently touching the steel mark with your fingernail.General domestic bearings or imitation bearings, steel marks are convex or concave in the bearing surface.
3. Overall situation
Whether A has appearance quality, poor processing quality and obvious circular runout? Bearing belongs to a kind of precision mechanical products, and the surface roughness must be below 1.6.
B whether there is muddy oil mark, domestic bearings are easy to leave thick oil mark, hold in the hand sticky thick, there is an obvious taste of antirust oil.Almost no trace of antirust oil can be seen on the original imported bearings.
C Whether the goods are genuine or not, there are obvious specifications and models such as CAK's inner hole has no cone shape, and 2RS has only unilateral seal.
4, metallic luster
Bearing quality depends on the level of steel and heat treatment.
A bearing chamfer is no longer polished after heat treatment. The genuine product's chamfer is quite smooth and has a gray metallic luster.There are two kinds of inferior goods. One is made of fake bearings made in China with good quality. The chamfer is also very smooth, but the color is not metallic luster of gray.The other is made with domestic small factory goods false, chamfering is not smooth, there are bump marks, not bright.
B bearing steel is divided into six categories: high carbon chromium bearing steel, chromium free bearing steel, carburizing bearing steel, stainless bearing steel, medium and high temperature bearing steel and anti-magnetic bearing steel.
● If rust spots are found, the material has problems.
● If serious collision marks are found, the material is defective.
● if found ball or roller thickness is not -, manufacturers jerry-built.
5. Listen to the sound
The left hand holds the bearing body sleeve, and the right hand stirs the coat to rotate it and listen to whether there is any noise.Because the production condition of most counterfeit products is backward, so when rotating, the noise will be issued.Completely manual workshop operation, in the production process will inevitably be mixed with sand and other impurities, hidden in the bearing body, so it will emit noise when rotating.This is the biggest difference between the factory brand which strictly implements the production standard and operates by machine.