Copper and Primary Nonferrous Metals: What the Comparison Can Establish

The global copper benchmark is $13,543/tonne as of Jul 2026. BLS WPU1022, Primary Nonferrous Metals, stands at 544.73index (1982=100) as of Aug 2026. This page previously described WPU1022 as copper mill shapes and treated the two series as a map of fabrication margins. WPU1022 covers a broader primary-metals population; it does not measure the prices of copper sheet, wire, tube or busbar. The underlying observations and stable links are retained, but those conclusions have been withdrawn.

Co-movement does not identify a margin

A copper price per tonne and a broad producer-price index may move together for several reasons, including shared inputs and economic conditions. Correlation does not identify how much a specific supplier passes through, and its residual is not a measurement of fabrication costs, tariff effects or supplier profit. Neither a ratio of price to index points nor that ratio's deviation from an average gives the percentage of an invoice available for negotiation.

Primary Nonferrous Metals PPI, Aug 2026: 544.73index (1982=100). The retained index ranges from 316.45 in May 2025 to 587.67 in June 2026.

A benchmark calculation with a clear scope

At the displayed global copper benchmark, 20 tonnes have a benchmark value of approximately $270,856. This is tonnes multiplied by price per tonne; it is not a delivered quote for fabricated products. Alloy, form, conversion, freight, terms and taxes require their own evidence. The former dollar estimates attributed to a fabrication wedge have been removed because the broad PPI cannot establish that wedge.

Measure pass-through from the contract

For an actual copper purchase, match benchmark changes to the contract's reference period, metal-content quantity, agreed escalator and separately quoted conversion charge. Compare like specifications and delivery terms. Use supplier invoices to test whether the agreed changes occurred; do not assume an aggregate index is the price your supplier received or that every unexplained difference is margin.

Enter matched invoice prices and quantities to calculate price variance without attributing unsupported causes. Measure actual purchase-price variance