Copper wire and cable scrap: why the same copper is priced four ways

Why insulated cable pays less than bare copper

It is easy to feel short-changed when a buyer offers far less for insulated cable than the published copper price. But the buyer is not paying for the weight you hand over. They are paying for the copper they can recover from it, after someone has done the work of stripping it. Understanding that difference is the key to pricing copper wire and cable, and to deciding whether stripping it yourself is worth the effort.

Four grades, four prices

The exact definitions vary by country and by buyer, so ask what thickness and cleanliness a buyer expects for each. Common names such as bare bright and ICW are explained in the Scrap Metal Terms Glossary, and the general principle of selling by grade is covered in How to Grade Your Scrap.

Why insulation costs you money

Insulation adds weight but no copper. A buyer pricing insulated cable works from the copper content, not the gross weight, and that content varies with the type of cable. For mixed cable, a recovery in the region of sixty to seventy percent copper by weight is a common rule of thumb, but it is only that. Thick power cable with thin insulation can recover much more, while fine multi-core flex or data cable can recover much less, because the plastic makes up most of its weight.

Three further costs sit on top of the lost weight. First, the buyer has to strip or granulate the cable, which takes machinery and labour. Second, the plastic left over has to be disposed of or sold on. Third, the buyer is carrying uncertainty: until the cable is stripped, they cannot be sure how much copper is inside, so they price in a margin of safety.

That last point is why a buyer who can see exactly what is in a lot will often offer more than one who cannot. A clear photo, an honest description of the cable type and a stated weight reduce the buyer's uncertainty, and a lower margin for uncertainty means a higher offer.

To strip or not to strip?

The decision comes down to simple arithmetic, and you can run it yourself with your own numbers.

1. Estimate the copper content. Strip a metre of the cable by hand, weigh the copper and weigh the original piece. The ratio tells you your recovery percentage.
2. Find the price gap. Check the reference price for bare bright and for insulated cable. The difference per kilogram of copper is what stripping adds.
3. Time the job. Time yourself stripping a measured length. Scale that up to your whole volume.
4. Compare. If the value added is clearly more than your time is worth, strip it. If not, sell it as it is.

For small amounts of thick cable, a sharp knife or a cheap hand stripper can be quick and worthwhile. For large volumes, a powered wire stripping machine pays for itself surprisingly fast, and many sellers choose to sell large quantities of cable to a buyer who has their own chopping line, rather than to invest in equipment. Whatever route you choose, treat the answer as one specific to your cable, not a rule for all cable.

The one thing never to do: burn it

Some sellers burn the insulation off cable to free the copper. Do not. It is illegal in most places, it releases toxic smoke including dioxins from burning PVC, it is a fire risk, and it damages the copper by oxidising the surface, which pushes the metal down to a lower grade and a lower price. A burnt-copper pile is also a signal to a buyer that the material may be suspect, and that can reduce their willingness to deal.

Check what you really have

Not every wire that looks like copper is copper, and the difference is large.

• Copper-clad aluminium (CCA). Common in cheap cable, it is aluminium with a thin copper skin. Scratch the end to look at the core: if it is silver rather than copper-coloured, it is aluminium. It is worth far less than solid copper.
• Copper-clad steel. A magnet will stick to it. It is found in some coaxial cable and grounding wire.
• Tinned copper. Copper with a thin tin coating, common in marine and electronic wire. It is copper, but the coating may place it in a different grade.
• Enamelled wire. Motor and transformer windings use fine copper wire with a varnish coating. It is valuable but needs processing, so it is usually graded separately.
• Mixed assemblies. Cable with connectors, steel armour or lead sheathing is graded on the whole assembly unless you take it apart.

Declaring CCA or plated wire as solid copper is the fastest way to a failed delivery. The buyer will find out on receipt, and a buyer has 24 hours after receiving the material to confirm it matches the listing.

Sort before you sell

A mixed lot of bare wire, number 1, number 2 and insulated cable typically prices at the lowest grade in the pile. Even a rough sort into separate containers usually adds up to more than the same material sold as one lot. Keep four containers if you can: bare bright wire, clean tube and heavy pieces, plumbing offcuts with solder or paint, and insulated cable. Keep brass fittings, steel clips and lead solder out of the copper. Brass fittings belong in their own container, as do aluminium parts. The ferrous and non-ferrous split in Ferrous vs Non-Ferrous Metals is the first pass.

If you are collecting copper regularly, for example from jobs as an electrician, plumber or demolition contractor, it also helps to keep a small log of weights and grades. Over time you will see which categories make the most money and where the sorting effort is best spent.

Frequently asked questions