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Bearings – Most Common Bearing Materials

Bearings – Most Common Bearing Materials
Issue Time:2018-07-02

Bearings are made of manydifferent materials, and many of these materials function more effectively incertain applications than others. Take a minute to learn about the manydifferent types of materials bearings can be made of:

1. Chrome Steel – SAE 52100

This is the most commonmaterial used for precision ball bearings, roller bearings, and tapered roller bearings. This still has a high levelof carbon within it and contains about 1.5% chromium.

These bearings have a highresistance to cracking and a hard surface, which helps them to resist wear andtear from rolling.

2. Extra Clean 52100 ChromeSteel

This type of steel is used tocreate precision miniature bearings. It is processed with additional meltingsteps. The resulting bearing is extremely quiet. Most often, the hardeningprocess is done in a controlled atmosphere furnace. The resulting product canoperate at temperatures up to 120°C.

SAE 52100 is by far the bestgeneral purpose steel for making bearings. It hardens to a very high level andhas a long life when actually in use. However, the low chromium level of 1.5%means these bearings are not very resistant to corrosion.

3. Martensitic Stainless Steel– AISI 440C

This type of bearing hashigher carbon content. The lower carbon content results in a softer material,however, it does allow for these bearings to be magnetic.

These bearings are slightlynosier than others, but they are able to operate at high temperatures of up to250°C.

4. Martensitic Stainless Steel– 440C – ACD34

This material has smallercarbides in order to minimize noise, while also offering the same corrosionresistance as 440C. This is one of the most widely used materials for bearings,and it can bear similar loads to that of chrome steel.

5. Austenitic Stainless Steel

Bearing components made fromthis type of stainless steel have a high resistance to corrosion and arenon-magnetic because they are made with low amounts of carbon. However, thismaterial cannot be hardened, so it only works with low loads and low speeds.