Why do different types of electrical wire — THHN, Romex, building wire — price differently for the same copper weight?
Short answer: The copper content itself is priced the same regardless of wire type, but insulation thickness and jacket construction vary a lot between wire types, which changes the effective copper-to-total-weight ratio. Romex-style sheathed cable has a thicker outer jacket plus individually insulated conductors inside, so it yields less copper per kilogram than a simple single-conductor THHN strand, which is why buyers often quote different rates per wire type even though the underlying metal is identical.
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List Free →Why construction matters more than the copper itself
Copper is copper — a buyer isn’t paying a different rate for the metal based on what it used to be wired into. What changes is the ratio of copper to total weight once insulation and jacketing are accounted for, since a buyer paying by weight for insulated wire is really estimating what percentage will convert to actual copper.
Why sheathed cable yields less
Romex-style non-metallic sheathed cable has an outer plastic jacket wrapped around individually insulated conductors, meaning more total insulation weight per meter than a simple single-conductor wire like THHN. That lower copper yield is reflected in a lower quoted rate per kilogram for sheathed cable versus simpler insulated types.
What to do if you have a mix
If you’re accumulating different wire types from an electrical job or teardown, ask the buyer whether they price by type or as one blended insulated wire rate — sorting by type, even roughly, protects the value of higher-yield wire from being averaged down.
How ScrapTrade Makes This Easier
ScrapTrade lets you list wire by type — THHN, Romex, building wire — so buyers can quote each accurately instead of one blended insulated-wire rate.
Ready to sell or source wire and cable scrap without the guesswork? ScrapTrade connects verified buyers and sellers with escrow-protected payments and transparent weighing.
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