+912267437972

+919022636025

enquiry@real-bolt.com

Contact Us
ISO 9001:2015 · UNS C70600–C71500 · ASTM B151

Cupro Nickel Fasteners Manufacturer, Supplier & Exporter with Superior Quality

Cupro Nickel fasteners offer outstanding resistance to marine corrosion and biofouling. We manufacture CuNi 90/10 (C70600) and CuNi 70/30 (C71500) fasteners for naval, offshore, desalination, and marine engineering applications.
Request a Quote
View Products

2

Grades

12

Products

-196°C

Min Temp

300°C

Max Temp

380 MPa

Min tensile strength · Cupro Nickel 70/30 per ASTM B151

Excellent

Seawater immune · biofouling resistant

8.95 g/cm³

Density (avg) · Cu-Ni binary alloy

The marine Cu-Ni alloy explained

What is Cupro Nickel Fasteners?

Cupro Nickel is a copper-nickel binary alloy series containing 9–33% nickel, providing outstanding resistance to seawater corrosion, biofouling and erosion-corrosion at flow velocities encountered in marine piping systems and heat exchangers. The two principal fastener grades — 90/10 (UNS C70600, 9–11% Ni) and 70/30 (UNS C71500, 29–33% Ni) — are named for their copper-to-nickel ratio and differ primarily in corrosion resistance and strength. Cupro Nickel fasteners are specified for ship seawater cooling systems, desalination evaporators, offshore platform firewater mains, naval vessel hull fittings and subsea pipeline clamps. The higher nickel content of 70/30 provides superior resistance to fast-flowing seawater (above 3 m/s) and is standard for naval and submarine applications under MIL-C-15726 and DEF STAN 02-834, while 90/10 serves standard commercial marine service at lower material cost.
PropertySpecification
Base ElementCopper (Cu)
Ni Content9–33%
Grades70/30 (C71500) and 90/10 (C70600)
Max Service Temperature300°C
Density8.90–8.95 g/cm³
ASTM StandardsB151, B122

Cupro Nickel grades — 70/30 or 90/10?

Multiple fastener grades and material grades are available for Cupro Nickel Fasteners, each offering distinct mechanical properties, corrosion resistance, temperature capability, and fatigue strength for demanding industrial fasteners and engineering applications. Compare the available grades to refine material selection for specific operating environments, industries, and performance-critical engineering requirements.

Grade UNS Ni % Key property Max temp Best application
Cupro Nickel 70/30 (Most popular) UNS C71500 29–33% Max seawater + erosion 300°C Naval, desalination View grade
Cupro Nickel 90/10 UNS C70600 9–11% Standard marine service 300°C Ship systems, offshore View grade
Cupro Nickel 70/30
Cupro Nickel 90/10

Cupro Nickel Fasteners — International Standards & Material Certifications

Cupro Nickel Fasteners from RealBolt Engineering Industries are manufactured to ASME SB-151 for rod and bar in both 90/10 and 70/30 grades. Naval orders are supplied to MIL-C-15726 with Lloyds Register or DNV certification; all batches ship with EN 10204 MTC 3.1/3.2 and full heat-number traceability.
Standards
DIN 931 DIN 933 DIN 912 DIN 934 DIN 125A DIN 127 ISO 4014 ISO 4017 ISO 4762 ISO 4032 ASME B18.2.1 ASME B18.3 ASME B18.2.2 BS 1768 BS 3692 BS 4190 IS 1367
Certifications
ISO 9001:2015 NACE MR0175 NABL Lab Lloyds Register MTC 3.1 / 3.2

Cupro Nickel Fasteners Applications — Industries & Use Cases

Cupro Nickel Fasteners from RealBolt Engineering Industries are specified by engineers and procurement teams across demanding industries where complete seawater corrosion immunity, biofouling resistance, and marine-grade corrosion protection for shipbuilding and offshore service is critical to fastener performance and service life. Primary end-use sectors for Cupro Nickel Fasteners include naval shipbuilding, offshore seawater systems, desalination plants, coastal power generation, and submarine fittings — click each industry below to see specific application details and recommended grades.
Cupro Nickel 90/10 and 70/30 fasteners are specified for ship seawater cooling systems, fire main piping flanges, hull fittings and sea chest connections. They resist seawater corrosion, biofouling and erosion-corrosion at flow velocities up to 3.5 m/s.
Cupro Nickel 70/30 fasteners are used in multi-stage flash (MSF) and multi-effect distillation (MED) evaporator tube bundle support hardware, tube sheet bolting and brine heater connections.
Offshore seawater lift pumps, injection flowlines and hypochlorite dosing system flanges use Cupro Nickel 70/30 fasteners for combined seawater corrosion and biofouling resistance.
Steam condenser water-box bolting and cooling water inlet/outlet flanges at coastal power stations specify Cupro Nickel for seawater and brackish water corrosion resistance in preference to carbon steel or SS 316L.
Naval applications requiring non-magnetic, biofouling-resistant and seawater-proof fasteners specify Cupro Nickel 70/30 per MIL-C-15726 for sea water valve hardware, thruster housings and through-hull fitting fasteners.

Cupro Nickel vs Monel vs Naval Brass

This comparison table helps marine architects, offshore engineers, and naval procurement teams evaluate Cupro Nickel Fasteners against Monel and Naval Brass options — covering seawater corrosion immunity, biofouling resistance, HF acid resistance, tensile strength, non-magnetic properties, applicable MIL and DEF STAN specifications, and relative material cost for marine and naval fastening applications. Use this data to make an informed alloy selection for your specific operating environment, design code, and budget — or contact RealBolt’s technical team for a project-specific recommendation.
Property Cupro Nickel 70/30 Monel 400 Naval Brass C46400
Seawater resistance Excellent Excellent Good
Biofouling resistance Excellent Good Moderate
Tensile strength (min) 380 MPa 517 MPa 483 MPa
HF acid resistance Poor Excellent Poor
Navy specification MIL-C-15726 MIL-N-894 N/A
Relative cost Medium High Low-Medium

Verdict: Cupro Nickel 70/30 is the standard for naval and offshore seawater systems with excellent biofouling resistance. Monel 400 adds HF acid resistance for alkylation plant duty. Naval Brass C46400 is adequate for marine deck hardware at lower cost.

Need Cupro Nickel fasteners? Get a competitive price today.

Partner with RealBolt Engineering Industries for certified Cupro Nickel Fasteners backed by full EN 10204 material test reports, competitive pricing, and reliable global delivery from our Mumbai facility. Our marine and naval technical team supplies Cupro Nickel Fasteners in 90/10 (C70600) and 70/30 (C71500) with Lloyds Register or DNV certification, MIL-C-15726 documentation for US Navy orders, and custom metric M6–M64 and UNC/UNF thread specials with EN 10204 3.1/3.2 material test reports. Request a quote today and receive a competitive price within 24 hours.
022-6743-7972
+91 90226 36025
Email Us

Cupro Nickel Fasteners — Common Questions Answered by Our Technical Team

Browse the expert answers below to the most frequently asked questions about Cupro Nickel Fasteners — covering 70/30 vs 90/10 selection for seawater and naval service, MIL-C-15726 and DEF STAN compliance, galvanic compatibility with stainless steel and carbon steel, biofouling resistance, available thread forms and sizes, and Lloyds/DNV certification documentation. If your question is not answered here, contact the RealBolt technical team directly for grade-specific guidance, project support, and competitive pricing on Cupro Nickel Fasteners.
Cupro Nickel 70/30 (UNS C71500, 29–33% Ni) has higher nickel content, providing better resistance to seawater velocity, erosion-corrosion and biofouling. It is preferred for high-velocity seawater (above 3 m/s) and naval applications. 90/10 (UNS C70600, 9–11% Ni) is more economical and adequate for standard marine seawater systems at lower flow rates.
Yes. Both 70/30 and 90/10 are fully resistant to seawater corrosion, including stagnant, flowing and tidal zone service. They are also resistant to biofouling — marine organisms attach less readily to Cupro Nickel than to stainless steel. This reduces maintenance requirements in offshore and naval applications.
Yes. Cupro Nickel and SS 316L are electrochemically compatible — the galvanic potential difference is small and does not cause accelerated corrosion of either material in seawater. Cupro Nickel is compatible with itself, naval brass, Monel and stainless steel. Avoid direct contact with carbon steel or aluminium alloys in seawater.
We supply Cupro Nickel fasteners in metric ISO threads (M6–M64), unified UNC/UNF (¼″–2½″), and BSW (Whitworth) threads for retrofit of older UK and Commonwealth naval equipment. Custom thread profiles are machined to order. All thread forms are available in 70/30 and 90/10 grades.

Industrial Cities We Serve:

  • Ahmedabad
  • Aurangabad
  • Bengaluru
  • Chennai
  • Coimbatore
  • Faridabad
  • Gandhidham
  • Greater Noida
  • Gurugram
  • Hazira
  • Hosur
  • Hyderabad
  • Jamnagar
  • Jamshedpur
  • Ludhiana
  • Mumbai
  • Mundra
  • Mysuru
  • Nagpur
  • Nashik
  • Navi Mumbai
  • Noida
  • Pune
  • Rajkot
  • Sanand
  • Surat
  • Thane
  • Tiruppur
  • Vadodara
  • Visakhapatnam

Countries We Export To:

  • US
  • Canada
  • Mexico
  • Germany
  • UK
  • France
  • Italy
  • Spain
  • Netherlands
  • Belgium
  • Poland
  • Sweden
  • Norway
  • Denmark
  • Turkey
  • UAE
  • Saudi Arabia
  • Qatar
  • Oman
  • Kuwait
  • Bahrain
  • South Africa
  • Egypt
  • Nigeria
  • Australia
  • New Zealand
  • Singapore
  • Malaysia
  • Indonesia
  • Thailand
  • Vietnam
  • South Korea
  • Japan
  • Brazil