BABBITT METAL

Content Tools

410 Hamilton St.,Washington, Ill. 61571

You have used it, and poured it into a journal-box. Have you ever wondered about what you were working with? Where did it get its name? What is it? What is a journal-box? Wellits a bearing to you; in this case a babbitted bearing. Steam engines, threshing machines and other old farm machines were full of it; you have nursed it and cursed it.

A journal bearing consists of two machine parts that rotate relatively to each other. The part which enclosed by and rubs against the other is called the JOURNAL (shaft of axel) and the part which encloses the journal is called the BOX or less specifically the BEARING. In the more common form of journal bearings, the journal rotates inside of a fixed bearing. In some cases, as in a loose pulley, the journal is fixed and the bearing rotates, while in other cases both the journal and the bearing have a definite motion, as for example, a crank pin and its bearing in the connecting rod.

Did you know that the 'inventor' of babbitt metal for bearings did not conside it important and did not have it patented? But he did go on and get a patent on the JOURNAL-BOX'.

Babbitt metal is one of our most important bearing metals today. The modern automobile you drive today depends on it. Babbitt metal is an alloy of tin or lead. It is classed as a white metal. Even white brass is in reality a babbitt metal. Other ingredients may be copper, antimony, nickel, phosphor bronze, silver, zinc, cadmium, and more. It has excellent anti-friction and corrosion resistance properties which set a standard for all bearing metals.

The alloy containing copper, tin and antimony is usually called GENUINE BABBITT METAL. According to the Society of Automobile Engineers, at one time, the following specifications will produce a high grade of babbitt that should give excellent results when used for such service as connecting-rod bearings, or any other machine bearings subjected to similar service: copper, 7%, antimony 9%, tin 84%. There are a large number of commercial grades of babbitt metals, many of which have a high percentage of lead and consequently sell at a low price.

The original mixture, by the inventor (who may be called the father of soft-metal bearings) in 1839, is supposed to have been 88.9% tin, 3.7% copper, 7.4% antimony.

The inventor of babbitt metal was ISAAC BABBITT (1799-1862), an American inventor, born in Taunton, Mass. Early in life he became interested in the production of alloys. He had very little schooling but by the time he was 24 years old he was a full-fledged goldsmith. Babbitt went to Boston in 1834 and obtained employment as superintendent of the South Boston Iron Works. Here he succeeded in making the first brass cannon ever cast in the United States.

It was also while with this company that Babbitt invented a journal-box and received United Slates patent no. 1,252 for it on July 17, 1839. The specifications for this patent contained an incidental suggestion that a good lining for the box to serve as the bearing surface for a journal or an axle could be had by melting up 50 parts of tin, 5 of antimony and 1 of copper. This alloy was found subsequently to be so satisfactory and was used so extensively that Babbitt's name became and has continued to be associated with it. The popularity and great utility of this alloy so overshadowed the journal-box invention that the latter was all but forgotten and there developed the general popular belief that Babbitt had invented a bearing metal, something that was never in his mind. On May 15, 1840, he received British patent no. 9,724 for his journal-box, and in 1847 the idea was patented in Russia.

Probably his largest award for the invention was that of $20,000, granted by Congress in 1842. The Secretary of the Navy in that year made a tentative agreement with Babbitt to purchase for $20,000 the rights to use his patented journal-box and 'anti-attrition' metal in the United States Navy. The agreement, together with letters of recommendation as to the value of the idea, including one from the prominent engineer, John Ericsson, was presented to Congress by Secretary Upshur during the third session of the 27th congress, and appears in HOUSE EXECUTIVE DOCUMENT no. 163. It's not know how long Babbitt continued with the Alger Foundry in the manufacture of journal-boxes. Overwork and the overstraining of an unusual brain eventually necessitated his commitment to an Asylum, where he died in his 63rd year.