Re: oiling journals (Was Holes, etc...)


Anthony Thompson <thompson@...>
 

Kurt Laughlin wrote:
Babbitt metal doesn't have a single defined composition, IIRC, but it is
mainly tin with about 10% copper. "Bronze" is kind of a generic term for
copper - tin alloys, so there is some overlap in the terms. Both are
characterized as copper alloys under the UNS Cxxxxx designation, as are
brasses, cupronickels, and nickel silvers.

In other words Larry, what some call "Babbitt" is called "bronze" by others.
C'mon, Kurt, that's like saying steel has carbon in it, so graphite is called "steel" by some. It's so silly a remark that I assume you're joking. I sure hope so.
There are indeed a number of different commercial Babbitt compositions. I assumed in Dennis's remark that he was referring to other soft bearing metals, of which there are several. I don't think he meant that bare bronze was used in freight car journals. If that was meant, I'd like to know the source of the info.
BTW, Kurt, "bronze" is actually a generic term for a number of copper alloys OTHER THAN brass, that is, alloyed with something other than zinc. There are phosphor bronzes and aluminum bronzes, to name just two. In fact, some copper alloy listings call the one we're speaking of as "tin bronze."

Anthony Thompson
Dept. of Materials Science & Engineering
University of California, Berkeley
thompsonmarytony@...

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