Copper Coated Aluminum (CCA) and Oxygen Free Copper Wire
Purchasing wire can be confusing. In addition to gauge and insulation type, we are now seeing designations like “CCA” and “OFC” applied. This article will attempt to clarify a few of these.
Copper Coated Aluminum
Copper is a commodity and the most expensive component in wire. So if a particular wire is significantly cheaper than others, you should be concerned about what you are actually getting. In our industry, we have seen wire mislabeled as the heavier gauge, or have excessively thick insulation to make it appear more than it is. Lately, in many cases, inexpensive wire is actually “CCA” wire.
‘CCA’ is Copper Clad/Coated Aluminum wire. This is ALUMINUM wire with a very thin coating of copper. At a glance it can appear the same as pure copper wire. The price may look attractive, but keep in mind that aluminum is only about 60% as conductive as copper. This means to carry the same load, you’d have to use a significantly heavier gauge wire, which can eliminate much of the cost savings. Substituting CCA wire for the same gauge copper wire is dangerous and can lead to burnt wiring or fires.
In addition is it less flexible than copper so it is harder to work with and the individual strands can break when overly flexed. It can also be more prone to corrosion. Although it may have some uses for AC wiring or applications where weight is a major issue, we feel the cost savings of CCA wire is not worth the downsides for general automotive use. We do not offer any CCA wire.
Regarding Oxygen Free Wire
You might see some places advertising OFC or Oxygen Free Copper Wire. Is this a worthwhile upgrade over ‘standard’ 100% copper wire?
For speaker wire, depending on who you ask, there may be some benefit to OFC wire.
According to Roger Russell, Electrical Engineer and Director of Acoustic Research at McIntosh Laboratory, even expensive "highly refined copper with silver impurities removed, and oxygen reduced to 0.0005%, has only one percent higher conductivity." And is "INSIGNIFICANT in audio applications." So it certainly isn’t a factor in powering an automotive accessory.
There is a more detailed discussion of the topic in THIS ARTICLE.
We’ll leave it up to you to determine if Oxygen Free wire is worthwhile in your speaker wiring. For non-audio use like powering your new light bar, there is no benefit to OFC and it is not worth paying a premium for.
For the record, Battery Cable, Primary, SXL, and Motor/1015 wire sold by Wiring Depot is all US made, 100% pure copper wire that is guaranteed to be true to spec. Most of our wire is produced by East Penn Manufacturing, although we do occasionally source from other US suppliers.