Which metal is most commonly used for outboard bearings?

Babbit is most commonly used for outboard bearings due to its unique properties. It is an alloy primarily made of tin, with a small amount of copper and antimony, which provides excellent wear resistance and low friction characteristics. These properties are essential in bearing applications, especially in situations where the metal will be subjected to significant stress and movement.

Babbit bearings are often used in applications that require high load capacities and performance under various speeds and temperatures. The alloy's ability to conform slightly under load ensures a good fit and reduces wear on both the bearing and the shaft it supports, which is crucial for the longevity and efficiency of machinery.

Other metals like zinc, brass, and magnesium may have applications in various machinery and fittings but do not provide the same level of performance needed for outboard bearings. Their mechanical properties or wear resistance do not match those of Babbit, making it the preferred choice in this specific application.