UNS C71500
Cupro-Nickel 70/30
Fasteners
Why Nickel Content Matters Here
UNS C71500’s roughly 30% nickel content is a genuinely significant step up from the lower-nickel 90/10 copper-nickel alloy (UNS C70600) — and that additional nickel buys two related but distinct benefits at sustained high-velocity seawater flow rates, where lower-alloy materials begin to suffer accelerated erosion-corrosion at the water/metal interface.
First, genuine erosion-corrosion resistance — as seawater velocity increases past a certain threshold, protective surface films on many materials get mechanically stripped away faster than they can reform, accelerating corrosion at flow-disturbed areas like elbows, tees, and around fastened joints. The 70/30 alloy’s higher nickel content forms a more resilient, faster-reforming protective film, giving it a genuinely higher safe velocity limit than lower-nickel alternatives.
Second, a well-documented natural resistance to marine biofouling — copper-nickel alloys as a family release a low, steady level of copper ions at their surface that inhibits the settlement of barnacles, mussels, and other marine organisms, a genuine and widely-cited property that reduces fouling-related flow restriction and maintenance burden in seawater piping systems compared to fouling-prone materials like plain steel or many stainless grades.
Akbar Fasteners Pvt. Ltd. exports to over 50 countries, and our UNS C71500 fastener range is manufactured and verified by chemical composition and mechanical testing under our ISO 9001:2015 quality system.
Where This Material Genuinely Applies
Genuine High-Velocity Erosion-Corrosion Resistance
A more resilient, faster-reforming protective film gives a higher safe seawater velocity limit.
Genuine, Natural Biofouling Resistance
Steady low-level copper ion release inhibits marine organism settlement.
The Standard Material in Its Class
A globally established, well-proven choice for demanding seawater piping systems.
Verified Mechanical Properties
Batch testing confirms genuine copper-nickel content and mechanical properties for every lot.
UNS C71500 vs UNS C70600 — Quick Reference
Confirming whether your system’s actual seawater flow velocity genuinely justifies the higher-nickel, higher-cost 70/30 alloy over the more economical 90/10 alternative. This table is the quick reference we use with buyers before quoting.
| Aspect | UNS C71500 (70/30) | UNS C70600 (90/10) |
|---|---|---|
| Nickel Content | ~30% | ~10% |
| Erosion-Corrosion Resistance | Genuinely higher velocity limit | Good, lower velocity limit |
| Biofouling Resistance | Genuine, well-documented | Genuine, well-documented |
| Best Suited For | High-velocity, demanding seawater flow | Moderate-velocity, cost-sensitive systems |
UNS C71500 Specification Details
Nominal Composition
- Copper ~65 – 69% (Balance)
- Nickel ~29 – 33%
- Iron ~0.4 – 1.0%
- Manganese ~1.0% Maximum
Typical Mechanical Range
- Condition Annealed / Cold Worked
- Erosion-Corrosion Resistance Genuinely Superior
- Biofouling Resistance Genuine, Natural
- Weldability Good, Standard Practice
Fastener Types We Manufacture
- Hex Bolts & Studs Standard & Custom Sizes
- Hex Nuts Standard & Heavy Hex
- Washers Matching Material
- Custom Machined Parts On Request
Application Areas
Wherever sustained high-velocity seawater flow, or genuine biofouling exposure, drives the material selection.
Seawater Cooling & Intake Systems
piping and flange fastening
Desalination Plant Piping
process piping fastening
Naval & Offshore Piping Systems
piping and hardware
Power Plant Condenser & Heat Exchanger Piping
cooling water systems
Standard Export Documentation
Prepared as standard practice for every UNS C71500 fastener shipment.
Mill Test Certificate (MTC)
Heat/lot number, chemical composition, and mechanical property verification for every batch.
Chemical Composition Report
Confirms actual copper, nickel, iron, and manganese content fall within the specified UNS C71500 range.
Certificate of Conformance
Confirms the shipment matches the purchase order specification in full.
Certificate of Origin (COO)
Confirms India as country of manufacture for destination customs purposes.
NABL Accredited Test Reports
Independent mechanical and dimensional testing available on request.
Commercial Invoice & Packing List
Itemized value, Incoterm, and detailed carton/weight breakdown for customs clearance.
Internationally Recognised Standards Coverage
Related Fastener Grades & Materials
UNS C64200 Aluminium Silicon Bronze
Our related copper-based alloy, valued for non-magnetic behavior and galling resistance against stainless.
View UNS C64200 →UNS C54400 Phosphor Bronze
Our fatigue-resistant, free-machining copper alloy, for cyclic loading rather than pure seawater flow service.
View UNS C54400 →ASTM A194 Grade 8M Nuts
Our chloride-resistant 316 stainless grade, an alternative where higher static strength is the priority.
View Grade 8M Nuts →Stainless Steel Fasteners Manufacturer India
Our broader fastener manufacturing capability across all major carbon, alloy, stainless, and non-ferrous grades.
View SS Manufacturer Guide →High-Velocity Seawater
or Biofouling Concerns?
Tell us your system’s flow velocity and service environment — we’ll confirm whether 70/30 genuinely fits, or whether 90/10 is the more economical match, and quote with full documentation. Akbar Fasteners Pvt. Ltd. responds within 24 hours.
Sales: +91 724 0000 733 · Support: +91 800 9315 333 · sales@akbarfasteners.in