FAQ

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We have a factory of 8000 square meters and than 50 CNC machines. We also have our own international sales department.

We now have than 100 employees

We specialize in chrome steel, stainless steel, and ceramic bearings, including than 18,000 types of ball bearings, roller bearings, angular contact bearings, thin-walled bearings, slewing ring bearings,plain bearings, linear bearings.

Our products cover a wide range of industries such as medical equipment, oil and gas extraction equipment, wind power generation, precision machine tools, automobiles and trucks, motorcycles, construction machinery, mining machinery, forklifts, agricultural machinery, textile machinery, household appliances, hardware, and power equipment.

Yes, we mainly do customized products according to customers’ drawings or samples.

We have than 20 production lines with an annual production capacity of than 50 million pieces of bearings.

First, we will check after each process. For finished products, we will inspect according to customer’s requirements and international standards.
Secondly, we have our own testing laboratory and complete testing equipment, including automatic hole measuring machine, outer diameter measuring instrument, vibration measuring instrument, noise measuring instrument, hardness testing machine, clearance measuring instrument, roundness measuring instrument, etc.

When we quote for you, we will confirm with you the transaction method, fob, cif, cnf, etc.
For mass production goods, you need to pay 30% deposit before production, and 70% balance payment against the copy of documents. The most common way is by T/T.

Usually we will ship the goods to you by sea, because we are in Shandong, and we are only 135 kilometers away from Qingdao port, it is very convenient and efficient to ship goods to any other countries. Of course, if your goods are very urgent, we can choose express for you, such as DHL, FEDEX.

The products are mainly exported to than 50 + countries and regions such as Europe, South America and Southeast Asia.

We have put together a collection of frequently asked questions (FAQs) about bearings (e.g. ball bearings, roller bearings, plain bearings, linear bearings) and bearing-related products (as well as bearing services). Just click on the questions you are interested in below, and you will get very concise, direct and accurate answers.

Yes, all bearings from AST are RoHS compliant. If you need proof of this fact, please contact us.
The full name of RoHS is the Restriction of Hazardous Substances Directive adopted by the European Union (EU), which came into effect in July 2006. RoHS is often referred to as the “lead-free directive”, but it restricts the use of the following six substances:

  • lead (Pb)

  • Mercury (Hg)

  • Cadmium (Cd)

  • Hexavalent chromium (Cr6+)

  • Polybrominated biphenyls (PBBs)

  • Polybrominated diphenyl ethers (PBDEs)

Yes, but it depends… In general, with small bearings, it is not economical to attempt to refurbish a bearing product. However, for larger size bearings (6″ bore and above), there may be economic benefits. In particular, bearings such as slewing rings, cylindrical roller bearings and spherical roller bearings are candidates for refurbishment. But beyond cumulative wear, there are many other factors involved in this financial decision, including maintenance intervals, lubrication, MTBF, environmental considerations, and .

Seals and shields are in place to prevent contamination from entering the bearings. In order of effectiveness, the housings are offered as follows: metal shield, rubber non-contact seal, Teflon non-contact seal and rubber contact seal. Not surprisingly, as the seal improves, so does the torque required to turn the bearing, as the seal/shield increases friction. Understanding the conditions and lifetime requirements of the application is important in determining the best guard or seal selection.

The ABEC scale is the industry accepted standard for ball bearing tolerances. It was developed by the Annular Bearing Engineering Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). There are five levels, from the widest tolerance to the tightest: 1, 3, 5, 7, and 9. Higher ABEC ratings provide better accuracy, efficiency, and higher speed capability, but don’t necessarily mean the bearing can spin faster. Additionally, ABEC ratings do not specify many other critical factors such as smoothness of rolling contact surfaces, ball accuracy and material quality.

While there may be a loose correlation between ABEC accuracy classes and noise, a higher ABEC class does not always mean a quieter bearing. ABEC ratings do not specify many other critical factors, such as smoothness of rolling contact surfaces, ball accuracy and material quality, all of which can affect noise.

Another major factor affecting noise performance is the lubricant type. For very quiet operation, it is very important to choose a quiet grease. Handling, mounting and proper preloading will also ensure the quietest possible operation.

AUB strongly recommends that you contact one of our bearing application engineers when selecting a design specification. AUB offers experienced sales and engineering personnel to assist in the design and selection process, maximize performance and ensure your success.

ABEC precision grades ABEC-1, ABEC-3, ABEC-5, ABEC-7, ABEC-9 are equivalent to ISO precision grades P0, P6, P5, P4, P2 respectively.

“Precision” and “Super Precision” are general bearing terms; however, in the bearing industry, there is no official definition of either. Generally, “precision” ball bearings meet ABEC-1 and ABEC-3 tolerances, while “super precision” ball bearings meet ABEC-5, ABEC-7 or ABEC-9 tolerances.

The most important factor in determining the shelf life of a “properly stored” bearing is lubrication. Greases and oils do have a shelf life (expiry date). We discuss this in detail in our white paper titled “Bearing Lubrication” and in our article titled “Shelf Life of Bearing Lubricants”.
Otherwise, if the bearings are stored properly (usually in their original factory packaging), the potential effects of contamination and oxidation will be minimal and will not significantly affect shelf life.

“Somewhat”… stainless steel is not rust proof, it is “corrosion resistant” and will rust over time in a corrosive environment. However, stainless steels corrode at a much slower rate than chrome alloyed steels. But it’s not that simple.

AUB Bearings offer bearings capable of spinning over 500,000 RPM. These are commonly used in experimental and defense applications. However, a bearing’s speed capability will depend on its size, the type and amount of lubricant used, bearing and cage materials, precision levels and tolerances, and how long it takes to reach maximum speed (among other factors).

There are several standard scales used to measure the hardness of materials, including Rockwell, Brinell, Vickers, and Shore. For bearings, the Rockwell scale is mainly used. However, even in the Rockwell hardness test, there are several different scales used to specify the hardness of different materials. Typically, the Rockwell “C Scale” is used to measure the hardness of bearing materials, since bearings are usually made of very hard materials.

Yes, samples are free, but the express fee is yours.

We will be responsible for all quality problems. And we have perfect after-sales rules within 12 months after shipment.

25-45 days for shipment, 7-10 days for samples.

Export standard packaging or special packaging according to customer requirements.