Chinese bearings market is significantly disorder in its' prices, quality definition and even bearing designations, it seems impossible to have a standard for Chinese bearings.  For example, 6310 deep groove ball bearings in Chinese market has its' possible prices ranging from RMB12 to RMB21, which is an extremely big range for a standard product.  Tengen Bearing Company, as the professional bearings supplier find it difficult to meet different needs from different customers.  Some are looking for great quality whilst some are seeking for competitive cost; one will not be attracted when they are not offered correctly.  That is why we defined the bearings quality classifications as in the chart, so to enable customers to benchmark Chinese bearings' quality as how we do.

Tengen Bearing Co., as the professional bearing supplier in China, with many years of local supply chain networks, we aim to offer the right bearings to the right customers at the right price.  We classify Chinese bearings into 3 grades, which are A, B, and C, as above bar chart shown with respective measured criteria.  The above comparison chart is generated based on a test conducted against three units of 6310 deep groove ball bearings made by three different manufacturers, who are in different segments of Chinese bearings market.  6310 deep groove ball bearing is the mostly common type of bearing in local market.  From the collected statistics of the test, we carefully analyze and plotted the differences as in the bar chart.

Chinese bearings’ quality is commonly being misinterpreted by many.  There are thoughts that lower quality bearings have lower precision level, and vise versa.  Let’s make an example from these three normal class 6310 deep groove ball bearings, in the result of test, all readings of Deviation of mean bore diameter in a single plane shows the pass figures which are within the range of 0 to -8 μm, as well as other tolerance standards such as Variation of mean bore diameter in a single plane and Deviation of mean outer diameter in a single plane.  Regardless which grade the bearing is, even the lowest grade of bearings are still meeting to the same tolerance requirements as clearly defined in JIS standard.

In Chinese market, the quality of bearings is usually differentiated by its’ manufacturer.  Larger manufacturers with relatively advanced machineries produce better quality bearings, whilst lower quality bearings are produced by smaller factories with less advanced machineries.  The differences of quality are greatly relied on the production engineering.  These may encompass material of bearings, machines that produce the bearings, as well as finishing of material such as heat treatment that will make a different in material hardness, and surface finishing such as surface roughness that will make another different in bearings appearance, you will be able to differentiate an SKF bearing out of a Chinese bearing at a glance.

In the chart, life span of bearings, maximum speed ratings, maximum load ratings, and its’ weight, are differentiating themselves one another, rather than their tolerance level. Based on these differentiated criteria and the test we have conducted, we concluded and classified Chinese bearings into Grade A, B, and C.  With this comprehensive classification of bearings grading in China, we aim to offer the right bearings to the right customers at the right price.

Note: The above bar chart is not intended for any other reasons but only for reference, please do not use it for other purpose.