Technical overview
C71500 (Copper-Nickel, 30%) contains 29–33% nickel with 0.40–1.0% iron. CDA lists it for seawater condensers, pump bodies and internal parts in seawater, salt-water flanges and piping, and corrosion resistance to 700 °F (≈ 370 °C).
Compared with 90/10 it has higher nickel and strength, and it is used where service conditions are more demanding.
Grades & standards
Grades are distinct materials — properties and uses below apply to the named grade only.
C71500
Copper-Nickel, 30%
Composition: Ni 29.0–33.0%, Fe 0.40–1.0%, Mn ≤ 1.0%, Zn ≤ 1.0%, Pb ≤ 0.05%, Cu remainder
- Seawater condensers and pump parts
- Corrosion resistance to 700 °F
- Weld wire and backing rings
Listed specifications: ASTM B111/B111M · ASTM B122/B122M · ASTM B151/B151M · ASTM B466/B466M · ASTM B171/B171M · AWS A5.6 (filler)
Technical properties
| Property | Value | Applies to | Source |
|---|---|---|---|
| Electrical conductivity | 4.6% IACS | C71500 | Copper Development Association Inc. |
| Melting range | 1171–1238 °C | C71500 | Copper Development Association Inc. |
| Specific gravity | 8.94 | C71500 | Copper Development Association Inc. |
Typical or specified values for the named grade from the cited source. Actual values depend on temper, size and the producing mill — rely on the mill certificate for your lot.
Forms
Typical industry forms for this material. They are not a stock list — form, size and availability are confirmed per enquiry.
- Seamless tube & pipe
- Plate & sheet
- Rod & bar
- Fasteners & fittings
Applications & industries
- Seawater condensers and heat exchangers
- Pump bodies and internal parts in seawater
- Salt-water flanges, fittings and piping
- Boiler and process equipment
Selection notes & limitations
- Not a drop-in replacement for 90/10 without engineering review.
What to specify when requesting a quote
- 1Pipe/tube OD and wall, or plate thickness
- 2Product standard and any naval / class-society requirement
- 3Grade and the standard it must conform to (ASTM, EN, IS, UNS or your drawing)
- 4Form and dimensions — thickness or diameter, width, length and tolerances
- 5Approximate quantity, and whether the requirement is one-off or recurring
- 6Intended application, so the grade can be cross-checked before quoting
- 7Documents required — e.g. mill test certificate, chemical analysis, certificate of conformity
- 8Delivery city / site and the date you need material by
Documents buyers may request
Mill test certificate
e.g. EN 10204 type 3.1 inspection certificate, where the producing mill issues one
Chemical analysis report
heat / lot composition against the specified grade
Certificate of conformity
confirming the material meets the ordered standard
Heat / lot traceability
heat numbers marked on material and documents
Dimensional inspection report
for cut-to-size or machined material
Safety Data Sheet (SDS)
especially for lead, beryllium-, cadmium- or lead-bearing products
Which documents can be provided depends on the source mill and is confirmed with each quotation.
Frequently asked questions
Is 70/30 always better than 90/10?
Not necessarily. 70/30 has higher nickel and strength, but 90/10 is widely specified and more economical. The right choice depends on the design code, flow and temperature.
Sources & technical references
- C71500 — Copper-Nickel, 30% (CDA alloy database) — Copper Development Association Inc. (CDA). Checked 2026-10-14.
