babbittry

Babbittry refers to the practice of using a soft metal alloy, known as babbitt metal, as a bearing material. This alloy is typically composed of tin, antimony, and copper, though lead-based versions also exist. The primary function of babbittry in a bearing is to provide a low-friction surface that can conform to the shaft, reducing wear and heat generation.

The concept of babbittry was developed by Isaac Babbitt in the 1830s. His invention revolutionized the design of bearings, particularly in steam engines and other machinery where high rotational speeds and loads were common. Before babbitt metal, bearings were often made from harder materials that were prone to seizing and rapid wear.

Babbitt metal is applied as a thin lining within a bearing housing. This lining is softer than the shaft it supports, allowing any minor imperfections or debris to embed themselves in the babbitt rather than damaging the shaft. This sacrificial nature of the babbitt prolongs the life of the more critical and expensive components of the machinery.

The properties of babbitt metal, such as its low melting point, excellent embeddability, and good anti-friction characteristics, make it suitable for a wide range of applications. These include automotive engines, industrial machinery, marine propulsion systems, and even large turbines. The specific composition of the babbitt alloy is often tailored to the operating conditions, such as temperature, load, and speed, of the particular application.