How Are Ball Bearings Made?

If you use machinery with rotary motion such as engines, turbines, and car wheels, bearings play a vital part in ensuring a smooth and efficient operation. Ball bearings may seem like simple elements, but they reduce the friction in rotational applications, thereby making your work easier. 

At SPB USA, we specialize in ball bearings that suit a variety of shape, material, and size requirements. You can get our ball bearings in steel, stainless steel, or chrome. Our ball bearings are in appliances such as pumps, office automation products, medical equipment, power tools, encoders, AC/DC motors, flow meters, and measuring devices. Read on for more details.

What Are Ball Bearings?

Ball bearings are rolling-element bearings that facilitate motion while also positioning moving machine parts, carrying loads, and reducing friction. Ball bearings rely on balls to separate two bearing rings or races. This helps to minimize surface friction and contact across moving parts. When the balls rotate, they cause a reduced coefficient of friction compared to when flat surfaces rub against each other. 

Ball bearings differ by the mechanism involved, with the most common ones being radial ball bearings or the rigid single row. The spherical ball bearings have minimal contact with their containing races, so they can transfer axial or radial loads with rapid, fluid motion. As the name implies, double-row ball bearings have two rows of balls; this design gives extra rigidity to the motion of the bearing. These bearings are mostly used in centrifugal pumps, electromagnetic clutches, and electric motors. Angular ball bearings have a side of the outer ring cut off to allow more balls to insert themselves.

How Are Ball Bearings Manufactured?

The ball bearing manufacturing process involves comprehensive procedures to ensure that the end products are smooth and perfectly round. 

1. Select material and cut rings. The initial process involves using an automatic machine to cut the rings to the recommended shape. The extra materials left after cutting are usually machined.
2. Stamp bearing with manufacturing information. The second step is to stamp the outer-ring faces with the necessary manufacturing information and bearing number. Access our Bearing Numbering System to learn more about bearing numbers.
3. Heat and harden. Next up is the hardening stage. Here, the rings go through a heating operation at 1,565° F for 15 to 20 minutes. The rings are then quenched in oil at 375° F for a duration of 15 to 20 minutes. The next step involves tempering the rings at 340° F for about two hours. 
4. Grind to proper dimensions. The rings then go through a grinding operation using specialized grinding machines to produce the desired finished dimensions. Race grinding helps to achieve race location, geometry, and radius. Face grinding ensures that the ring has a proper bearing width. Bore grinding is then applied on the inner rings while grinding is for the outer rings.
5. Apply final finishing. Finally, the races go through a honing process to bring out a perfect surface finish and geometry.

Some bearings, such as the angular contact bearing, may require additional grinding steps to ensure the inner and outer rings have the same width.

Custom Solutions from SPB USA

If you were wondering how ball bearings are made or were questioning what they are, now you have the right answer. Ball bearings are essential elements in various components from power tools to pumps, motors, flow meters, and more. At SPB USA, we are the go-to specialists for all your ball bearing needs. We have premium EZO bearings with bore diameters from the extra-miniature of 0.0236″ to a large of 3.543″. Contact us for more details about our products or to request a quote.