Are Ball Bearings Magnetic

Recently, there’s been a trend on various social media platforms and people are asking “Are ball bearings magnetic” Oh, you haven’t found an answer to that either. Read on to discover the uniqueness of magnetic ball bearing, its materials, and all other necessary information about this precious bearing.

What Are Magnetic Bearings?

Magnetic bearings are types of bearings that assist load through their magnetic levitation features. These types of bearings can support moving parts without physical contact. In other words, magnetic bearings utilize magnetic forces to partly or fully suspend the rotor without having contact with the casing.

The Magnetism Of The Ball Bearing Is Based On The Type Of Material

Particular materials can determine the magnetism of ball bearings, they are; Martensitic stainless steel, Ceramic, Soft magnetic alloys, Rare Earth magnets, and chrome steel. 

Martensitic Stainless Steel (AISI 440c, 420)

Stainless steel ball bearings are a product of chromium. The chromium helps them to resist corrosion and rust. These types of bearings are good for harsh environments. Although there are lots of stainless steel grades that are not magnetic, some stainless steel ball bearings that are made with martensitic stainless grades like 440C and 420 are magnetic.

Rare Earth Magnet (Neodymium Iron Boron, Samarium Cobalt)

Ball bearings that are made of rare earth magnet support loads through their magnetic levitation. Although they do not directly have contact between the moving parts, they reduce friction, minimize premature wear, and they do not need lubrication. In conclusion, they are indeed magnetic because they make use of the rare earth magnetic field to maintain rotation and stable levitation of the shaft in the system.

Ceramic (Silicon Nitride, Si3N4)

Ceramic ball bearings use ceramic balls instead of steel balls. These types of bearings are manufactured with ceramic materials like silicon nitride, which gives higher speed, generates lower heat, and minimizes friction. In addition, these types of bearings will work smoothly in higher temperatures and they don’t easily wear out. However, ceramic ball bearings are not magnetic.

Soft Magnetic Alloys (Silicon Iron, Nickel Iron)

Ball bearings that are produced from soft magnetic alloy silicon iron or nickel-iron offer high permeability and low coercivity. The purpose of this material in ball bearings is to ensure the bearings magnetize and demagnetize easily. These types of ball bearings are made of magnetic materials, but the overall magnetic properties of the bearings are usually based on their treatment and specific design. 

Plastic

These types of ball bearings are lightweight, give good wear resistance, work smoothly in corrosive environments, and they’re products of nylon or acetal. Most times they have balls that are made from stainless steel, glass, or plastic. Plastic ball bearings are a good fit for applications where resistance to corrosion and non-magnetic properties are crucial. In conclusion, plastic ball bearings being non-magnetic, makes it a good fit in sensitive electronic or magnetic fields.

Chrome Steel

These types of ball bearings are known for their durability and high load capacity, which is why they are mostly recommended for different applications. They are a product of chromium alloy steel, they have excellent hardness and high wear resistance, which makes them one of the best for high-speed applications. In conclusion, chrome steel ball bearings are magnetic because they have high carbon content and chromium.

 Conclusion

Whether ball bearings are magnetic or not depends on the materials the manufacturer uses in the production process. Trying to attract ball bearings with a magnet to see if they are magnet or not is another proven way to know if they are magnetic.