Composition of Babbitt Materials

Babbitt alloys possess excellent conformability and embeddability. These materials are not used in applications where operating temperatures exceed 300°F, but have relatively low compressive and fatigue strength. The commonly used compositions of bearing materials are:

• Tin-base babbitts with 89% Sn, 8% Pb and 3% Cu
• Lead-base babbitts with 75% Pb, 15% Sb and 10% Sn
• Copper alloys such as Cu- 10% to 15% Pb

Babbitts can also be made of other materials, such as tin or leaded bronze, copper lead alloy, aluminum bronze or alloys, and cast iron, which are widely used in many applications.

Bearing Materials

An integral part of designing a bearing is selecting the material, since the bearing materials constitute an important part in the journal bearing. This maxim is particularly important for Babbitt bearings. The materials that are chosen are especially significant when considering the beginning of the hydrodynamic lubrication process, when contact occurs between the rotating shaft and the bearing. The bearing materials must be soft enough to resist the wear and endure load under gas pressure. In addition, they must also possess good compressive and fatigue strength.