C70600 Copper-Nickel Prices November 2, 2026

C70600 is a 90/10 copper-nickel alloy - nominally 90% copper and 10% nickel, with deliberate additions of iron and manganese. It is the standard material for seawater piping, condenser and heat-exchanger tubing, shipboard cooling systems, desalination plant piping and offshore platform firewater loops. Its two properties that no other common copper alloy matches are resistance to flowing seawater erosion-corrosion and natural resistance to marine biofouling.

Both of those properties come from the iron, not the nickel, and that is the single most important thing a buyer can know about this alloy. C70600 carries 1.0–1.8% iron by specification, and that iron migrates to the surface in service to form a thin, adherent, iron-rich oxide film over the cuprous oxide layer. The film is what resists erosion-corrosion at velocity - without adequate iron the alloy still resists static seawater well but fails rapidly once water is moving, which is exactly the service it is bought for. Manganese is added as a deoxidiser and sulphur getter, and it improves hot workability.

Sources: published exchange assessments, merchant nickel premium indications, mill printed quotes by product form (week ending Oct 30, 2026). Reference trading day: November 2, 2026.

That $0.088/lb went somewhere. Here is the accounting, and it is worth understanding because it tells you how much of the next copper decline will actually reach you.

The line to take away is the nickel premium. A melt shop making C70600 does not buy LME nickel - it buys nickel cathode, briquettes or pellets at LME plus a physical premium, and that premium moved from $0.35/lb to $0.48/lb this week, a 37% increase, on tightening Class 1 supply. At 10% nickel content that is roughly $0.013/lb of real cost that the exchange price does not show you, and mills pass it straight through. That is why the melt value can fall 1.31% while the metal in the furnace costs nearly the same as it did last week.

The second reason is timing, and it favours waiting only if nickel stops rising. Copper-nickel has a three-to-five-week melt-to-quote pass-through - longer than brass, because nickel is bought on a separate procurement cycle from copper. The November 2 melt decline is not in the November 2 quote; it lands in the December print. Hold two scenarios side by side: if copper keeps falling and nickel steadies, waiting four weeks saves you another $0.10–0.15/lb. If nickel keeps rising at this week's rate, the nickel leg adds roughly $0.023/lb per week and eats the entire copper benefit within two weeks. Watch the nickel premium, not the copper headline.

Every C70600 product form starts from the same $6.539/lb melt value. Everything above it is conversion, and the conversion share ranges from 23.5% on plate to 52.4% on fittings - which tells you immediately where negotiation has room and where it does not.

Two decisions follow directly from that table. On plate, bar and sheet you are buying metal with a conversion surcharge - those are the forms where a melt decline reaches you fastest and where waiting has the most value. On condenser tube, U-bends and fittings the conversion leg is 39–52% of the price, so metal moves are muted and capacity is what sets both price and date. Condenser tube at 10–14 weeks and U-bends at 11–15 weeks are the longest lead times in the whole line, and they are driven by bending, stress-relief and inspection capacity rather than by alloy availability. If a package needs both plate and tube, order the tube first.

One substitution is worth checking on every pipe enquiry: welded B467 pipe at $9.58/lb against seamless B466 at $10.08/lb is $0.50/lb back and roughly two weeks faster, and for most seawater, firewater and ballast service the weld seam is not the limiting factor. Seamless remains the right call for high-pressure, high-velocity or class-coded pressure boundary work - but that should be an engineering decision, not a habit.

Nickel rising changes this comparison, and this week it moved in a direction most buyers will not expect. C71500 carries roughly 30% nickel, so it fell only 0.23% this week while C70600 fell 1.31%. The consequence: the C70600 discount against 70/30 widened from $0.286/lb to $0.357/lb - 90/10 got $0.071/lb cheaper relative to 70/30 in a single week.

The practical rule for this week: if your design velocity is inside 90/10's 2.4–3.0 m/s ceiling and you are currently on 70/30, the case for stepping back to C70600 is $1.81/lb on condenser tube, and it got stronger this week. The reverse is also true and matters more for safety: if your velocity exceeds 3.0 m/s, do not solve it with a heavier C70600 wall - erosion-corrosion is a velocity problem, not a thickness problem, and the correct move is C71500 at 3.6–4.5 m/s. Note also that pure copper is $0.107/lb cheaper on melt and completely unsuitable for this service. C70600 is not an upgrade from copper; it is a different material class.

C70600 failures in service are rarely about the alloy being wrong. They are about a certificate that was in specification and still described material that will not survive your duty.

Iron, and specifically the iron value - not just "within 1.0–1.8%". Iron is the element that produces the erosion-resistant film. A certificate that reports Fe at 1.02% is compliant and inadequate. For flowing seawater, put "Fe 1.2% minimum, actual value reported" on the RFQ. It costs about $0.03–0.05/lb to hold iron in the upper half of the band, and it is the cheapest insurance on the whole order.

Sulphur and lead, at 0.02% and 0.05% maximum. Sulphur forms a low-melting nickel-sulphide eutectic that causes hot cracking during welding and hot forming, and lead does the same through hot shortness. Both pass a compositional check and both can ruin a fabrication. If the part will be welded, ask for both actual values.

Nickel at the low end, with manganese as the tell. Nickel at 9.1% with manganese at 0.15% is a melt that was held to minimums across the board. Nickel at 10.2–10.6% with manganese at 0.6–0.9% is a properly controlled heat. The composition is legal either way; only one of them is what you meant to buy.

Condition, hardness and residual stress. Annealed, light-drawn or stress-relieved are not interchangeable, and if the service contains ammonia or ammonium compounds, residual stress plus ammonia is a stress-corrosion mechanism that applies to copper-nickel too. Specify the temper, require stress relief where ammonia is present, and ask for the hardness reading as evidence.

C70600 appears under different designations in every major standard system, and the equivalences are close but not always interchangeable - the differences are usually in iron, manganese or residual limits, and those are exactly the elements that govern velocity resistance and weldability. Use this table to translate a drawing, then confirm the specific product standard before you substitute.

Mill-direct C70600 (90/10 copper-nickel) across plate, sheet, strip, pipe, tube, bar, wire and fittings, with iron held in the upper half of the specification band on request and the actual Ni, Fe and Mn values reported on every certificate. Equivalent grades supplied to EN CuNi10Fe1Mn (2.0872), GB BFe10-1-1, JIS C7060 and BS CN102 chemistry on request.

Request A C70600 Quote