Table 6-5.--Identification of Metals by Chip Test
Copper, brass, and bronze can be rather easily
identified by a welder. Aluminum is a white metal.
The ring test, or the sound of the metal test, is an
Aluminum alloys, zinc, and the like, are all of
easy means of identifying certain metals after some
somewhat the same silver-gray color although they
experience with this method. It is used extensively for
may vary in shade.
identifying heat-treated steels from annealed steels. It
is also used to detect alloys from the virgin metal. An
example is the difference between aluminum and
duralumin, an alloy of aluminum and copper (2017-T)
(the letter T indicates that the metal is heat treated).
Metals may also be differentiated by means of the
The pure aluminum sheet has a duller sound, or ring,
weight or density test of the specimen. A good
than the duralumin, which is somewhat harder and has
example of identification by density or specific
a more distinct ringing sound.
gravity is identifying aluminum and lead. Roughly
speaking, their colors are somewhat similar, but
anyone may readily distinguish between the two
metals because of their respective weights. Lead
The magnetic test is another method used to aid in
weighs about three times as much as aluminum.
the general identification of metals. Frequently, the