General characteristics of babbitts

Antifriction alloys on the basis of lead or tin with low melting point which are used for casting between rubbing parts of mobile units were invented by American Isaac Babbitt in 1839.

• Tin B88, B83, B83C (containing Sn, Sb, Cu) were developed by Babbitt
• lead B16, BN, BSb (containing Pb, Sn, Sb, Cu)
• calcium BKA, BK2, BK2SH (containing Pb, Ca, Na).

In Eastern Europe the first two groups of babbitt are the most popular. The composition of tin babbitts according to GOST 1320−74 includes up to 90% Sn, up to 6% Cu and up to 9% Sb. The second group on the basis of lead is regulated by GOST 1209−90.

Advantages of

Babbitts are very ductile at normal temperatures, have a t° of melting — not higher than 440 ° C. They have an extremely low coefficient of friction They remarkably reduces the wear of rubbing parts, increase the efficiency of equipment. The performance of plain bearings is determined by the thickness of the babbitt layer on the steel liner. Babbitts combine high ductility. They accelerate the run-in to the mating surfaces; they are able to retain lubricants but are hard enough to support the shaft. As a result, shaft wear is reduced. These advantages are achieved by the special structure of babbitts: the hard grains are bonded together by a plastic base. The hard particles serve as a base for the shaft to work on and withstand high specific pressures, while the soft base ensures accelerated run-in of the shaft and retains the grease.

Mechanical properties of B83

_σc — Ultimate short-term strength, [MPa]

_σT — yield strength for permanent deformation, [MPa].

Disadvantages

Babbitt alloys are not resistant to shock loads and vibration, which often hinders the operation of moving parts. The low strength allows the use of babbitts only in bearings with a strong housing based on steel or non-ferrous alloys.

Production and use

The most commonly used babbitts are of the following composition:

• 9/10 Sn, 1/10 Cu;
• 8/10 Pb, 1/6 Sb, 1/20 Sn;
• 89% Sn, 7% Sb, 4% Cu.

Mg, Na, Ni, Ca, Cd, arsenic, tellurium are used for alloying babbitts. To improve sliding, the alloy is applied to the bearing liners. Tin babbitts of B88, B83, B83C, SAE11, SAE12, ASTM2 grades have high ductility and excellent sliding properties. Compared to lead babbitts, they are more resistant to corrosion, wear and conduct heat better. Lead babbitts (B16, BN, BSb, BKA, BK2, BK2Sh, SAE13, SAE14, ASTM7, SAE15, ASTM15) are cheaper and more heat resistant.

Area of application

Bearings of rolling mills, compressors, diesel engines, moving units of heavy machinery that do not experience shock loads. Lead-calcium babbitt is used in. motor-axle bearings of electric locomotives and other parts of railway rolling stock.

Supply

We supply certified fusible alloys at the best price. The specification reflects the data on the percentage composition and mechanical properties of the products. From us it is easy to buy in bulk any semi-finished products for large-scale production. We provide services to retail buyers. The high level of service, compliance with GOST and international quality standards, responsiveness of service is the face of our company.

Buy at favorable price

All alloys sold by Evek GmbH meet GOST and international quality standards. We supply babbitts of all grades and solders in the shortest terms. High quality, reasonable prices and a wide choice of products determine the face of our company. By becoming our regular customer, you can count on a system of discount discounts. Cooperation with us will help you realize any engineering plans. We are waiting for your orders on our site.