Bronze: The most common porous bearing material. It contains 90% copper and 10% tin. These bearings are wear-resistant, ductile, conformable, and corrosion-resistant. Their lubricity, embeddability, and low cost give them a wide range of applications from home appliances to farm machinery.
Leaded Bronzes: Have a 20% reduction of the tin content of the usual 90-10 bronze and a 4% reduction in copper. Lead content is 14% to 16% of the total composition and results in a lower coefficient of friction and good resistance to galling in case the lubricant supply is interrupted. These alloys also have higher conformability than 90-10 bronzes.
Copper-Iron: The inclusion of iron in the composition boosts compressive strength although the speed limit drops accordingly. These materials are useful in applications involving shock and heavy loads and should be used with hardened shafts.
Hardenable Copper-Iron: The addition of 1-1/2% free carbon to copper-iron materials allows them to be heat treated to a particle hardness of Rockwell C65. They provide high impact resistance and should be used with hardened-and-ground shafts.
Iron: Combine low cost with good bearing qualities, widely used in automotive applications, toys, farm equipment, and machine tools. Powdered iron is frequently blended with up to 10% copper for improved strength. These materials have a relatively low limiting value of PV (on the V side) but have high oil-volume capacity because of high porosity. They have good resistance to wear but should be used with hardened-and-ground steel shafts.
Leaded-Iron: Provide improved speed capability, but are still low-cost bearing materials.
Aluminum: In some applications, they provide cooler operation, greater tolerance for misalignment, lower weight, and longer oil life than porous bronze or iron. The limiting PV value is 50,000, the same as for porous bronze and porous iron.”