In the Digest of May 16th Hal Davis gives an explanation for the term
"white metal".  He states that the correct term should be "Hoyt metal",
suspecting a similarity in sound when pronounced quickly.  He doesn't
say what this "Hoyt metal" actually is.

I don't have information at hand on Mr. Hoyt.  When I was a purchaser
for a company that was using lots of soldering metals, especially
tin-solder, one of the suppliers was a factory in Holland, called "De
Nederlandse Witmetaal Fabrieken".  Literally translated: "The Dutch
White Metal Factories".  I presume that the term "white metal" is the
same as the Dutch equivalent "witmetaal", or the German "Weissmetall".

This "witmetaal"-lemma is explained in my dictionary as being: an alloy
of tin with antimony, with or without an addition of copper, led or
zinc."

 [ Problem: my 1927 dictionary says that 'white metal' is a term
 [ used in the Welsh method of copper smelting; it contains 77 to 79%
 [ copper; the tin content is not defined.  We really need the
 [ definitions used by the metal industry (and you provide the DIN
 [ specs next -- excellent! :)  -- Robbie

My encyclopaedia refers to "bearing metals".  There I read: "bearing
metals are alloyed metals or alloys", explained by: "Alloys: metals
suitable to be used as contact-layer in slide-bearings; for the purpose
of it they must consist of a rather soft mass with embedded hard parts."

Generally spoken, following this definition, bearing metals are: cast
iron, tin and lead-bronze, as well as sintered bearings (for so called
self- greasing bearings).

In a more specific way a group of alloys with a high amount of tin is
meant, with a suitable addition of antimony and copper, sometimes also
with smaller amounts of cadmium and nickel (sometimes also named by the
terms "witmetaal" (white metal) or "anti-friction metal)."

I have an old German technical handbook, published in 1929 by the
Berg-Heckmann-Selve group of metal producing companies.  In it they
list their products.  The Germans standardize many technical products,
using the Deutsche Industrie Norm, or DIN, like the British with the
B.S. or British Standard.

In this handbook we also find the related DIN-standards for the
products of these factories, amongst which: "DIN 1703: Weismetall fuer
Gleitlager und Gleitflaechen" (White metal for slide-bearings and
slide-surfaces).  I'm not aware of the latest version of this
DIN-standard, but the version in my book is from 1925, and lists eight
materials, all with a certain amount of tin as a major component.

It looks to me that white-metal is an alloy with a high percentage of
tin.  As such this group of alloys belongs to the bigger group of
bearing metals.

By the way: there often is a misunderstanding involved: what is called
light metal (most of the time moulded parts out of aluminium alloys)
often also is called white metal.  This however is not correct.

A reason for the confusion may be that an alloy of aluminium can get
corroded, and the surface is then covered by a kind of white powder.

Another reason may be the fact that the words "white" and "light" do
sound very identical.

I'm curious now what kind of material "Hoyt's metal" is.  Is there a
US standard describing this metal?  And who was Mr. Hoyt?

Jan Kijlstra

 [ These jargon names are confusing.  I've always called junky castings
 [ 'pot metal', but now I see I was wrong.  (_Pots_ are made from 'pot
 [ metal !)  We really need the names defined as they were in the
 [ 1910s and '20s, in the UK, USA and Europe.  Can you folks with old
 [ metallurgy books help?  And we shouldn't forget Phillip Morgan's
 [ problem in Digest 980515: what can be done for old castings which
 [ are deteriorating?  -- Robbie