What Are Babbitt Bearings and What Is the Repair Process?

by Allen Jones Canadian Writer

Babbitt metal

In 1839, the American inventor Isaac Babbitt created a bearing made of a light-colored, tin-based metal alloy — Babbitt metal. This metal — also known as Babbitt bearing or bearing metal — is bonded to the lining of sleeve bearings widely used today in engine bearings. Also sometimes referred to as white metal, this latter term may also refer to other bearing alloys, including zinc die-casting metal.

The alloys used in Babbitt bearings — including in Canadian Babbitt bearings — are melted down and cast to create the bearing surface. The finished result is most frequently utilized as a fine surface layer in multiple-metal, complex structures.

Advantages of Babbitt Bearings

One of Babbitt bearing metal’s main characteristics is its ability to resist galling — wear caused by adhesion between sliding surfaces. Canadian Babbitt bearing metal is typically soft but is also comprised of small solid crystals, turning it into a metal matrix composite, or MMC. As bearings degrade, the soft metal erodes and creates paths for lubricants to travel between the high, hard areas that make up the bearing surfaces.

Babbitt bearing materials are chosen based on their corrosion resistance qualities, their resistance to degradation during contact, and their dimensional stability. When tin is used as the softer metal, any friction will cause it to melt, turning it into a lubricant that can protect bearings from damage in the absence of other lubricants.

Babbitt bearings naturally provide a low coefficient of friction, so that even in the absence of lubrication, they will have much less friction than other metals — such as steel or cast iron. When a lubricant is added, Babbitt bearings can provide an even lower friction coefficient than ball bearings.

Applications of Babbitt Bearings

In many applications, babbitt bearings will last for more than ten years. The following products rely on Babbitt bearings to support their shaft’s weight:

● Gas turbines
● Hydraulic turbines
● Compressors
● Electric motors
● Gear drives
● Pumps
● Bearings
● Ball mills
● Rod mills
● Sag mills

Babbitt Bearing Repair

Babbitt metal in bearings absorbs the damage from chemical contamination or structural failures to protect the structure’s shaft and therefore requires regular maintenance, repairs, and replacements.

Typical Babbitt bearing repair steps include:

● Reconditioning
● Water jackets cleaning
● Housing repairs
● Insulating

Malfunctions and unscheduled downtime can be costly for any business. Often, a cold repair process is used that features a lock and lacing process without the use of heat to eliminate the risk of damage. Safety tests may include:

● Hydrostatic testing
● Ultrasonic testing
● MEG testing

Visit us to talk to a Babbitt bearing expert today. Depending on the shaft’s surface speed, load-bearing and cooling facilities, and other key factors, Canada Metal’s experts will help you select the optimal Babbitt metal to suit your requirements.