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Cupro Nickel 70/30 Nuts Manufacturer & Exporter in India

Explore Cupro Nickel 70/30 Nuts Manufacturer & Exporter in India manufactured for demanding industrial applications with reliable strength, corrosion resistance and compliance with international standards.
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-200

Min Temp

1000

Max Temp

🌡

1000

Suitable for continuous service up to approximately 1000°C under typical operating conditions.

⚡

700

Typical tensile strength around 700 MPa depending on product form and heat treatment.

🛡

Excellent

Excellent corrosion resistance in a wide range of industrial environments.

⚖

8.9

Typical density is approximately 8.9 g/cm³.

Product Overview

What are Cupro Nickel 70/30 Nuts?

Cupro Nickel 70/30 nuts are corrosion-resistant fasteners manufactured from a copper-nickel alloy containing 70% copper and 30% nickel, designated as UNS C71500. These nuts are produced from ASTM B151 or B122 bar and rod, offering excellent resistance to seawater, brine, and non-oxidizing acids. The addition of iron and manganese enhances their strength and imparts superior resistance to impingement and erosion corrosion, making them ideal for marine and offshore applications.

Cupro Nickel 70/30 nuts are widely specified for use in heat exchangers, condenser tube sheets, shipbuilding, and desalination plants, where long-term durability and immunity to biofouling are critical. They are available in hex, heavy hex, and lock nut configurations, conforming to international standards such as DIN 934, ISO 4032, and ASME B18.2.2.

Quick Specifications

MaterialCupro Nickel 70/30
UNS NumberC71500
DIN Number2.0882
Material StandardASTM B151 / B122
Nut Standard (Metric)DIN 934 / ISO 4032
Nut Standard (Inch)ASME B18.2.2
Thread FormISO Metric / UNC / UNF
Diameter RangeM6-M64 / ¼"-2½"
Tensile Strength245 MPa (35.5 ksi) min
Yield Strength105 MPa (15.2 ksi) min
HardnessMax 80 HRB
? All material certified by NABL-accredited laboratory. PMI and ferrite testing available on request.

Complete the Fastener Set

Other Cupro Nickel 70/30 Fastener Products Available from RealBolt

RealBolt also manufactures the complete Cupro Nickel 70/30 fastener range from certified copper-nickel alloy bar stock, including Cupro Nickel 70/30 Bolts, Cupro Nickel 70/30 Screws, Cupro Nickel 70/30 Washers, Cupro Nickel 70/30 Studs, and Cupro Nickel 70/30 Threaded Rods. All Cupro Nickel 70/30 fastener types are produced to ASTM with full EN 10204 MTC 3.1/3.2 documentation.
Cupro Nickel 70/30 Bolts
Cupro Nickel 70/30 Screws
Cupro Nickel 70/30 Washers
Cupro Nickel 70/30 Studs
Cupro Nickel 70/30 Threaded Rods

Technical Data

Cupro Nickel 70/30 Nuts Dimensions, Sizes & Thread Standards

Cupro Nickel 70/30 Nuts are available in metric M6–M100 and inch ¼″–4″ as standard. Per DIN 934 (hex nut) / ISO 4032 / ASME B18.2.2. Custom thread pitches and special lock nut designs available. Inch and metric sizes supplied. All Cupro Nickel 70/30 nuts dimensions conform to applicable DIN, ISO, and ASME B18 standards.

Hex Nut Dimensions - Metric (DIN 934 / ISO 4032)

Size (M)Pitch (mm)A/F (mm)Height (mm)Min D (mm)Max D (mm)
M61.0105.066.2
M81.25136.588.2
M101.5178.01010.2
M121.751910.01212.2
M162.02413.01616.2
M202.53016.02020.2
M243.03619.02424.2
M303.54624.03030.2
M364.05529.03636.2
M424.56534.04242.2
M485.07538.04848.2
M565.58545.05656.2
M646.09551.06464.2

Dimensional & Material Standards

StandardCoversThread
DIN 934Hex nutsMetric
ISO 4032Hex nutsMetric
ASME B18.2.2Hex & heavy hex nutsUNC/UNF
ISO 7040Prevailing torque lock nutsMetric
DIN 985Lock nuts, nylon insertMetric
Material StandardRequirement
ASTM B151Bar/rod - UNS C71500
ASTM B122Plate/sheet - UNS C71500
EN 12165Forgings
EN 10204 3.1Mill test certificate
EN 10204 3.2TPI-witnessed MTC

Material Chemistry

Cupro Nickel 70/30 Chemical Composition

Cupro Nickel 70/30 Nuts are manufactured from a copper-nickel alloy with nickel (9–33%), iron (1–2%), and manganese additions per ASTM and MIL-C-15726. Iron additions are essential — they form a protective surface film that resists seawater impingement and erosion-corrosion at flow velocities up to 3.5 m/s in shipboard piping and offshore cooling systems.

Chemical Composition per ASTM B151

ElementComposition (%)
Copper (Cu)65.0-70.0%
Nickel (Ni) incl. Cobalt29.0-33.0%
Iron (Fe)0.4-1.0%
Manganese (Mn)1.0% max
Zinc (Zn)1.0% max
Lead (Pb)0.05% max
Phosphorus (P)0.02% max
Other elements0.5% max (total)
? All heats verified by NABL-accredited spectrometry. PMI available on request.

Why Cupro Nickel 70/30 Alloy Composition Matters for Nuts

High Nickel Content (29–33%) — Seawater Resistance
Nickel enhances resistance to chloride-induced corrosion and biofouling, making Cupro Nickel 70/30 nuts ideal for marine and desalination plant use.
Iron & Manganese — Erosion & Impingement Resistance
Iron and manganese additions improve resistance to high-velocity seawater and turbulent flow, preventing nut degradation in condenser and heat exchanger assemblies.
Low Impurity Levels
Strict control of lead, phosphorus, and zinc ensures mechanical integrity and prevents stress corrosion cracking in critical fastener applications.

Fastener Performance

Cupro Nickel 70/30 Nuts Mechanical Properties & Torque Reference

The table below lists mechanical properties and torque reference for Cupro Nickel 70/30 Nuts per ASTM. Cupro Nickel 70/30 nuts achieve 700 MPa tensile strength, with hardness, yield, and elongation values verified by NABL-accredited testing and reported in the EN 10204 MTC.

Nut SizeRecommended Torque (Nm)Clamp Load (kN)
M124518
M1611032
M2022050
M2438075
M30750120
M361300175
M422000240
M483000320
?? Anti-seize: Use copper-based anti-seize for marine service. Lubricated values assume K=0.18. Retorque after thermal cycling in condenser or heat exchanger applications.

Industry Applications

Cupro Nickel 70/30 Nuts Applications — Industries & End Uses

Cupro Nickel 70/30 Nuts from RealBolt are specified across marine shipbuilding, offshore seawater systems, and naval defence where excellent corrosion resistance and 700 MPa tensile strength are required for reliable fastener performance. Click each industry below for detailed application examples.
Cupro Nickel 70/30 nuts are the preferred choice for hull fastenings, seawater piping flanges, and propeller shaft couplings due to their outstanding resistance to biofouling and seawater corrosion. Used extensively in naval and commercial vessels.
Hex nuts and lock nuts for high-pressure brine piping, evaporator tube sheets, and pump assemblies in reverse osmosis and multi-stage flash desalination plants, where stainless steel is prone to chloride attack.
Nuts for tube sheet assemblies, water box covers, and cooling water system flanges in thermal and nuclear power plants, ensuring long-term reliability in aggressive cooling water environments.
Cupro Nickel 70/30 nuts are specified for splash zone and topside piping, firewater systems, and riser clamps on offshore oil and gas platforms, where resistance to seawater and brine is critical.

Cupro Nickel 70/30 Nuts Standards & International Certifications

Cupro Nickel 70/30 Nuts from RealBolt Engineering Industries are manufactured to internationally recognised fastener dimensional standards covering thread form, tolerances, strength grades, and quality requirements. Every batch ships with EN 10204 MTC 3.1/3.2, Lloyds Register or DNV certification, NACE MR0175, and PMI (XRF) reports — available on request for all orders.
Standards
DIN 934 ISO 4032 ASME B18.2.2 BS 1768 BS EN ISO 4032 IS 1364 IS 1367
Certifications
ISO 9001:2015NABL LabPED 2014/68/EUMTC 3.1 / 3.2

Buy Cupro Nickel 70/30 Nuts from India's Leading Manufacturer — Get a Competitive Quote Today

Partner with RealBolt — India’s leading manufacturer of certified Cupro Nickel 70/30 Nuts — for competitive pricing, EN 10204 MTC 3.1/3.2 documentation, and fast Mumbai dispatch. Standard sizes are ex-stock; custom dimensions accepted with 2–3 week lead time. Request your quote today.
022-6743-7972
+91 90226 36025
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Answers for Buyers

Cupro Nickel 70/30 Nuts — Frequently Asked Questions

Browse expert answers to common questions about Cupro Nickel 70/30 Nuts from RealBolt — covering 70/30 vs 90/10 selection, ASTM B151, seawater immunity, MIL-C-15726 approval, sizes, and Lloyds/DNV certification. Contact our technical team directly for project-specific guidance on Cupro Nickel 70/30 nuts selection and pricing.
Cupro Nickel 70/30 nuts are available to DIN 934 (hex nut), ISO 4032, ASME B18.2.2 (inch hex and heavy hex), and DIN 985 (nylon insert lock nut). Custom prevailing torque and slotted nut designs can be supplied to ISO 7040 and DIN 937. Special threads (BSW, BSPP, NPT) are available on request.
Yes – Cupro Nickel 70/30 nuts are specifically designed for continuous seawater immersion and are immune to biofouling, pitting, and impingement corrosion. They are the industry standard for shipbuilding, desalination, and offshore piping systems. No additional coating or cathodic protection is required.
Use a copper-based anti-seize compound (such as Molykote 1000 or Loctite LB 8008) for marine and condenser service. This prevents galling and ensures easy removal after long-term exposure to seawater. Avoid nickel-based anti-seize for copper alloys.
No MOQ for standard metric and inch sizes (M8-M36) held in stock – single piece orders are accepted for urgent repairs. Custom sizes or special thread forms may require a 5 kg minimum. Bulk discounts apply at 50, 200, and 500 pieces.

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