Babbitt (alloy)

Babbitt metal is most commonly used as a thin surface layer in a complex, multi-metal assembly, but its original use was as a cast-in-place bulk bearing material.

Internal combustion engines use Babbitt metal which is primarily tin-based because it can withstand cyclic loading.

A steel shim is inserted to protect the face of the lower bearing and to space the cap of the pillow block away from the shaft.

When the bearing is disassembled the blue fills the hollows and is rubbed off the high spots, making them visible.

The high spots are scraped down, and the process repeated, until a uniform and evenly distributed pattern of blue shows when the shaft is removed.

Before the advent of low cost electric motors, power was distributed through factories from a central engine via overhead shafts running in hundreds of Babbitt bearings.

Ford was known to use two 0.002" on each cap and Babbitt that was 86% tin, 7% copper, 7% antimony (see the KRW catalogs for the Model T).

Poured Babbitt bearings are also known to fail gracefully, allowing the car to be driven for extended periods of time.

Ball and roller bearings can also be used in configurations that are required to carry both radial and axial thrusts.

In selecting the proper type of Babbitt for a particular job there are a number of factors to take into consideration, the most important of which are as follows: There is no doubt that if a bearing is to be highly loaded in relation to its size, a high-tin alloy is desirable; whereas for much lower-speed work and less heavily loaded bearings, a lead-based Babbitt may be employed and is far more economical.

In this case the technician's greatest concerns are: Eco-Babbitt is an alloy of 90% Sn, 7% Zn, 3% Cu that is not technically a Babbitt metal.