Welding
Non-Ferrous
Metals
Treating
Welding
Cast Iron
Welding
Ferrous
Metals
6
Appendix
C
Tests
for Identifying Metals (continued)
Chip
Test. If a high-speed grinder is not
available, or the results of a spark test seem inconclusive, a chip test with
a small cold chisel and hammer will
often reveal striking differences between metals of similar surface appearance.
The table below summarizes the chipping
characteristics of five types of ferrous metals. Appearance
Size
of Facility
of
Chip Chip
of
Chipping Gray
Cast Iron Small
partially 1/8
in. Not easy
broken chips Malleable
Iron Noticeably
longer 1/4 to
Very tough; harder to
than
those from 3/8
in. chip than
gray iron gray
cast iron Low
Carbon Steel Can
be made con- Almost
Very easy and
Cast Steel tinuous;
chisel any
leaves smooth groove
length High
Carbon Steel Fine
grain fracture Almost
Difficult, due to
noticeable, although
any hard
ness of metal chip
may be continuous length
Nickel
or Monel MetaI
Chipping
characteristics are so similar to those of low-carbon steel that chip
test
cannot distinguish one from the other.
