While U.S. automakers are using more copper wiring in their
vehicles, the growing number of applications doesn't
necessarily signal a boon for domestic wire drawers and
Two key factors account for this an ongoing push toward
wires with smaller gauge and wall sizes, and a looming threat
of material substitution. Copper wire producers' business also
fluctuates with the inclination of customers-especially
insulation producers-to integrate and produce their own
There is no question that consumers are demanding more and
more electronic gadgets and advanced creature comforts in their
vehicles, including such things as power and heated seats,
power windows and "infotainment" devices such as navigation
systems and video players, an executive at a major copper wire
fabricator said. "All of this drives demand for copper wiring,"
the executive added.
Whether this demand will benefit copper wire fabricators and
drawers is contingent on a number of variables, including
whether insulation companies, which have become increasingly
vertically integrated over the years, will opt to fabricate the
wire themselves or farm that business out to wire drawers, he
"There has been a long-time trend of more insulator
companies fabricating copper into wire, assembling the wire
with their insulation and selling the finished product to
harness manufacturers," the fabricator executive said. "But
more recently, with the economic downturn, some insulators are
going back to using outside wire fabricators like us, rather
than doing it themselves."
Another factor that threatens to limit copper consumption is
a big push on the part of automakers for smaller-gauge wire
with smaller wall thicknesses. "This trend has been occurring
for at least the past three or four years and I don't see it
stopping," the fabricator executive conceded.
The automakers are pushing for smaller-gauge wire not only
to increase the fuel efficiency of their vehicles but also to
reduce the size of the wiring harness to make room for more
gadgets, a source at a large copper wire drawer said.
The price volatility of copper is another driving factor.
"Over time, automakers will try to reduce the amount of copper
they use as much as possible," the wire drawer source said.
"Wire gauges just keep getting smaller and smaller," the
wire fabricator executive said. "Just a few years ago, 18 gauge
was a lot more popular. Previously we were seeing a lot of 12
to 14 gauge. Now certain types of wire are even going to 26
gauge, although that accounts for a very small part of the
The 26-gauge wiring uses less copper not only because of the
size, but also because it is made with copper alloys rather
than pure copper in order to meet testing requirements, the
wire drawer source pointed out. "The technology for us to use
pure copper at such small sizes isn't there yet."
Wire wall sizes also are shrinking, with a push toward
lighter crosslinked polyethylene insulation, including GXL, an
intermediate insulation wire, and TXL, the thinnest, lightest
and lowest cost of such wires. There's also SXL, the
second-thickest of the crosslinked polyethylene insulation
wires and thus more costly, which is used where more protection
is needed from potential mechanical damage.
"Twenty years ago wires had SXL walls. Now they have gone to
GXL and TXL walls and there is talk of going to ultra-thin
walls," the wire drawer source said. "They have gone from walls
as thin as 16 mils to 10 to 12 mils, and some customers are
already asking for 8-mil-thick walls," the source added. "The
problem is, we still need to maintain the same performance
attributes. That takes a good amount of engineering (and the
use of different compounds) to accomplish."
The ultimate question is, how low can it go. "There is a
limit. Copper is copper," the wire fabricator executive
The wire drawer source is convinced the industry will
continue to be asked to test that limit. "We will be asked to
take it as far as the technology allows and to force technology
as needed," she said, although doing so could hurt the bottom
line for wire drawers. "From a production point of view, you
don't want to make such small-gauged wire. You can just go so
small and still remain profitable."
Meanwhile, the threat of material substitution looms. "There
has been some talk of substitution by aluminum or copper-clad
aluminum, but I haven't seen much come of it yet," the wire
fabricator executive said.
To date, about the only area where some substitution has
taken place is the battery cable, which weighed more compared
with other wiring to begin with, the wire drawer source said,
adding that with copper prices climbing as much as they have
lately, material substitution is more of a front-burner issue
than it had been in the past. "But while aluminum is lighter
weight, the overall size of the wire would need to be bigger in
order to get the same conductivity as pure copper. But even
with the larger size, it would be lighter and generally less
expensive," she allowed.
That wouldn't have been the case years ago, when copper was
selling for about 85 cents per pound, the wire fabricator
executive said, but it is a different story with the metal now
trading at $3 to $3.50 per pound.
Even so, copper claims a number of features offsetting its
In addition to conductivity, copper is "more malleable" and
therefore easier to work with.
Aluminum is a very different metal to work with, the wire
drawer source said. "A lot of people know how to work with
copper and are more comfortable with it."
"I think the future is positive for copper wiring," the wire
fabricator executive said. "I am skeptical that it could be
replaced with other materials. It will remain the main part of
the electrical harness."