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Cupro Nickel 70/30 Nuts

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Manufacturer, Exporter & Supplier of Cupro Nickel 70/30 Nuts

Cupro Nickel 70/30 Nuts for Marine, Offshore & Industrial Applications

Cupro Nickel 70/30 Nuts are precision-engineered fastening components manufactured from copper-nickel alloy C71500, designed for high-performance applications in aggressive marine and industrial environments. Known for their exceptional resistance to seawater corrosion, biofouling, and stress corrosion cracking, these nuts are widely used in offshore platforms, shipbuilding, desalination plants, and heat exchanger assemblies.

Cupro Nickel 70/30 Nuts Manufacturer

Compliant with international standards such as ASTM B151, DIN, and ISO specifications, Cupro Nickel 70/30 nuts ensure mechanical integrity even under cyclic loading and saline exposure. Their stable microstructure and resistance to dezincification make them a preferred choice over conventional brass or stainless steel fasteners in marine conditions.

KK Fasteners manufactures these nuts with strict process control and supplies them to global clients across oil & gas, marine engineering, and power generation sectors, offering full traceability and export-grade packaging.

Technical Specification List Of Cupro Nickel 70/30 Nuts

ParameterDetails
MaterialCopper Nickel Alloy (CuNi 70/30 - UNS C71500)
GradeASTM B151, ASTM B122, DIN 86019
Size RangeM3 to M100 / 1/8" to 4"
Thread TypeMetric (ISO), UNC, UNF, BSW, BSF
StandardsDIN 934, ISO 4032, ASTM A194 (adapted)
Type VariantsHex Nuts, Heavy Hex Nuts, Lock Nuts, Jam Nuts
Surface FinishPlain, Polished, Passivated
Tensile StrengthMinimum 360 MPa
Hardness70–100 HB (Brinell)
Temperature Range-196°C to +300°C

Chemical Composition Of Cupro Nickel 70/30 Nuts

Cu-Ni 70/30 Cu Pb Mn Fe Zn Ni
88.6 min 0.05 max 1.0 max 1.8 max 1 max 9-11 max

Mechanical Properties Of Cupro Nickel 70/30 Nuts

Density Melting Point Yield Strength (0.2%Offset) Tensile Strength Elongation
8.1 g/cm3 1443 °C (2430 °F) Psi – 35,000, MPa – 241 Psi -80,000, MPa -551 30 %

Equivalent Grades for 70/30 Cu-Ni Nut

STANDARD UNS WERKSTOFF NR.
Cupro Nickel 70/30 C71500 2.0882

Dimensions of Cupro Nickel 70/30 Hex Nuts

Hex Nut Dimensions

All measurements in millimeters

Nominal Size or Basic Major Thread Diameter
F
G
H
Width Across Flats
Width Across Corners
Thickness
Basic
Max
Min
Max
Min
Basic
Max
Min
1/4
.2500
1/2
.500
.488
.577
.556
15/64
.250
.218
5/16
.3125
9/16
.562
.546
.650
.622
19/64
.314
.280
3/8
.3750
11/16
.688
.669
.794
.763
23/64
.377
.341
7/16
.4375
3/4
.750
.728
.866
.830
27/64
.441
.403
1/2
.5000
7/8
.875
.850
1.010
.969
31/64
.504
.464
9/16
.5625
15/16
.938
.909
1.083
1.037
35/64
.568
.526
5/8
.6250
1-1/16
1.062
1.031
1.227
1.175
39/64
.631
.587
3/4
.7500
1-1/4
1.250
1.212
1.443
1.382
47/64
.758
.710
7/8
.8750
1-7/16
1.438
1.394
1.660
1.589
55/64
.885
.833
1
1.0000
1-5/8
1.325
1.575
1.876
1.796
63/64
1.012
.956
1-1/8
1.1250
1-13/16
1.812
1.756
2.093
2.002
1-7/64
1.139
1.079
1-1/4
1.2500
2
2.000
1.938
2.309
2.209
1-7/32
1.251
1.187
1-3/8
1.3750
2-3/16
2.188
2.119
2.526
2.416
1-11/32
1.378
1.460
1-1/2
1.5000
2-3/8
2.375
2.300
2.742
2.622
1-15/32
1.505
1.433
1-5/8
1.6250
2-9/16
2.562
2.481
2.959
2.828
1-19/32
1.632
1.556
1-3/4
1.7500
2-3/4
2.750
2.662
3.175
3.035
1-23/32
1.759
1.679
2
2.0000
3-1/8
3.125
3.025
3.608
3.449
1-31/32
2.013
1.925
2-1/4
2.2500
3-1/2
3.500
3.388
4.041
3.862
2-13/64
2.251
2.155
2-1/2
2.5000
3-7/8
3.875
3.750
4.474
4.275
2-29/64
2.505
2.401
2-3/4
2.7500
4-1/4
4.250
4.112
4.907
4.688
2-45/64
2.759
2.647
3
3.0000
4-5/8
4.625
4.475
5.340
5.102
2-61/64
3.013
2.893
3-1/4
3.2500
5
5.000
4.838
5.774
5.515
3-3/16
3.252
3.124
3-1/2
3.5000
5-3/8
5.375
5.200
6.207
5.928
3-7/16
3.506
3.370
3-3/4
3.7500
5-3/4
5.750
5.562
6.640
6.341
3-11/16
3.670
3.616
4
4.0000
6-1/8
6.125
5.925
7.073
6.755
3-15/16
4.014
3.862

Different Types of Cupro Nickel 70/30 Nuts

  • Cupro Nickel 70/30 Flanged Nuts
  • Cupro Nickel 70/30 Hex Nuts
  • Cupro Nickel 70/30 Square Nuts
  • Cupro Nickel 70/30 T Nuts
  • Cupro Nickel 70/30 Nylock Nuts
  • Cupro Nickel 70/30 Lock Nuts
  • Cupro Nickel 70/30 Heavy Hex Nuts
  • Cupro Nickel 70/30 Jam Nuts
  • Cupro Nickel 70/30 Coupling Nuts
  • Cupro Nickel 70/30 Hex Cap Nuts
  • Cupro Nickel 70/30 Hex Flange Nuts
  • Cupro Nickel 70/30 Hex Weld Nuts
  • Cupro Nickel 70/30 Square Thin Nuts
  • Cupro Nickel 70/30 Square Weld Nuts
  • Cupro Nickel 70/30 Acorn Nuts
  • Cupro Nickel 70/30 Lifting Eye Nuts
  • Cupro Nickel 70/30 Wing Nuts
  • Cupro Nickel 70/30 T-Slot Nuts
  • Cupro Nickel 70/30 Nylock Jam Nuts
  • Cupro Nickel 70/30 K Lock Nuts
  • Cupro Nickel 70/30 9 Way Lock Nuts
  • Cupro Nickel 70/30 All Metal Lock Nuts
  • Cupro Nickel 70/30 Slotted Castle Nuts
  • Cupro Nickel 70/30 19 Point Flange Nuts
  • Cupro Nickel 70/30 Lug Nuts
  • Cupro Nickel 70/30 Open Lug Nuts
  • Cupro Nickel 70/30 Dome Nuts
  • Cupro Nickel 70/30 Hex Machine Screw Nuts
  • Cupro Nickel 70/30 Hex Lock Nuts Nylon Insert
  • Cupro Nickel 70/30 Hex Jam Nuts
  • Cupro Nickel 70/30 Hex Jam Nylon Lock Nuts
  • Cupro Nickel 70/30 Cap Nuts
  • Cupro Nickel 70/30 Prevailing Torque Lock Nuts
  • Cupro Nickel 70/30 Top Lock Nuts
  • Cupro Nickel 70/30 Pin-Lock Nuts
  • Cupro Nickel 70/30 Castle Nuts
  • Cupro Nickel 70/30 Flange Nuts SerSSted
  • Cupro Nickel 70/30 Machine Hex Nuts
  • Cupro Nickel 70/30 Finished Hex Nuts
  • Cupro Nickel 70/30 Forged Eye Nut
  • Cupro Nickel 70/30 Rivet Nuts
  • Cupro Nickel 70/30 Slotted Hex Nuts
  • Cupro Nickel 70/30 Acme Hex Nuts
  • Cupro Nickel 70/30 Anco Locknuts
  • Cupro Nickel 70/30 Flexloc Nuts
  • Cupro Nickel 70/30 Reversible Lock Nuts
  • Cupro Nickel 70/30 Panel Nut
  • Cupro Nickel 70/30 Poly Nut
  • Cupro Nickel 70/30 Conelock Nut
  • Cupro Nickel 70/30 Self Clinching Nuts
  • Cupro Nickel 70/30 Domed Cap Nuts
  • Cupro Nickel 70/30 Imperial Thread Nuts
  • Cupro Nickel 70/30 Imperial Thread Nylock Nuts
  • Cupro Nickel 70/30 Sleeve Nuts
  • Cupro Nickel 70/30 Thin Nuts
  • Cupro Nickel 70/30 Weld Nuts
  • Cupro Nickel 70/30 High Nuts
  • Cupro Nickel 70/30 Cage Nuts
  • Cupro Nickel 70/30 Security Nuts
  • Cupro Nickel 70/30 Imperial Nuts
  • Cupro Nickel 70/30 Industrial Nuts
  • Cupro Nickel 70/30 Miscellaneous Nuts
  • Cupro Nickel 70/30 Insert Nuts
  • Cupro Nickel 70/30 Knurled Nuts
  • Cupro Nickel 70/30 Round Nuts

Key Technical Features

  • Superior Seawater Corrosion Resistance — The CuNi 70/30 composition resists chloride-induced corrosion and erosion, making it ideal for long-term marine exposure.
  • Anti-Biofouling Properties — Natural resistance to marine organism growth reduces maintenance in submerged systems.
  • High Mechanical Strength — Designed to handle tensile loads up to 360 MPa, ensuring structural reliability in dynamic assemblies.
  • Thermal Stability — Maintains mechanical integrity across a wide temperature range, suitable for cryogenic and elevated temperature conditions.
  • Excellent Fabrication Compatibility — Compatible with welding and machining processes, ensuring integration into complex assemblies.
  • Dimensional Accuracy — Manufactured within ISO tolerance classes, ensuring consistent thread engagement and load distribution.
  • Resistance to Stress Corrosion Cracking — Performs reliably in high-stress saline environments where stainless steel may fail.
  • Long Service Life — Reduced replacement frequency lowers lifecycle costs in offshore and marine installations.

Industry Applications

Cupro Nickel 70/30 nuts are primarily used in marine and industrial systems where corrosion resistance and durability in saline environments are critical.

  • Shipbuilding & Naval Vessels — Used in hull structures, piping systems, and propulsion assemblies exposed to seawater.
  • Offshore Oil & Gas Platforms — Secures structural components and pipelines subjected to harsh marine climates.
  • Desalination Plants — Ideal for fastening heat exchanger units and brine handling systems.
  • Power Generation (Coastal Plants) — Used in condenser systems and cooling water circuits.
  • Chemical Processing Equipment — Suitable for handling corrosive fluids with chloride content.
  • Heat Exchangers & Condensers — Ensures leak-proof assembly in high-pressure thermal systems.
  • Marine Piping Systems — Used in flanges and valve assemblies transporting seawater.
  • Defense & Naval Engineering — Preferred for mission-critical applications requiring long-term reliability.

Manufacturing & Quality Assurance

Cupro Nickel 70/30 nuts are typically manufactured through hot forging followed by precision CNC machining to achieve accurate threading and dimensional tolerances. The process ensures grain refinement, improving mechanical strength and fatigue resistance.

Quality control includes dimensional inspection using calibrated gauges, hardness testing, tensile verification, and surface finish evaluation. Each batch undergoes chemical composition analysis to confirm compliance with ASTM standards.

KK Fasteners maintains ISO 9001-certified processes with full lot traceability, ensuring every shipment meets international compliance requirements including RoHS and REACH directives.

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Send us your Requirement for Cupro Nickel 70/30 Nuts

We can assure you one of best prices in the Industry. We respond to all enquiries with in 4-8 hours on all business days. Send us your requirement on inquiry@kkfasteners.com
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Cupro Nickel 70/30 Nuts - FAQs

Cupro Nickel 70/30 nuts are industrial fasteners made from copper-nickel alloy C71500, consisting of 70% copper and 30% nickel. They are specifically designed for use in corrosive environments, particularly seawater systems, offering excellent resistance to biofouling, stress corrosion cracking, and long-term degradation.

The difference lies in composition and performance. Cupro Nickel 70/30 provides higher strength and superior resistance to erosion and corrosion in high-velocity seawater compared to 90/10, which is better suited for moderate marine conditions and less demanding applications.

Cupro Nickel 70/30 nuts are typically manufactured in accordance with ASTM B151, DIN 934, and ISO 4032 standards. The material conforms to UNS C71500 specifications, ensuring consistent chemical composition and mechanical performance for industrial and marine applications.

These nuts are ideal for offshore platforms, shipbuilding, desalination plants, and marine piping systems where exposure to seawater and chloride-rich environments is constant. They are also used in heat exchangers and condensers due to their resistance to corrosion and scaling.

A reliable supplier should offer ISO-certified manufacturing, full material traceability, and compliance with ASTM/DIN standards. KK Fasteners, for example, provides documented quality checks, export-ready packaging, and supports global supply requirements for industrial buyers.

Cupro Nickel 70/30 Nuts - Export Destination

Cupro Nickel 70/30 Nuts Supplier in North America
Antigua and Barbuda, Bahamas, Barbados, Belize, Canada, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago, United States.
Cupro Nickel 70/30 Nuts Supplier Fasteners in South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Falkland Islands, French Guiana, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela.
Cupro Nickel 70/30 Nuts Supplier in Europe
Albania, Andorra, Austria, Belarus, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic (Czechia), Denmark, Estonia, Finland, France, Germany, Greece, Holy See, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Monaco, Montenegro, Netherlands, North Macedonia, Norway, Poland, Portugal, Romania, Russia, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine, United Kingdom.
Cupro Nickel 70/30 Nuts Supplier in Asia
Afghanistan, Armenia, Azerbaijan, Bahrain, Bangladesh, Bhutan, Brunei, Cambodia, Cyprus, Georgia, India, Indonesia, Iran, Iraq, Israel, Japan, Jordan, Kazakhstan, Kuwait, Kyrgyzstan, Laos, Lebanon, Malaysia, Maldives, Mongolia, Myanmar, Nepal, Oman, Pakistan, Palestine, Philippines, Qatar, Saudi Arabia, Singapore, South Korea, Sri Lanka, State of Palestine, Syria, Taiwan, Tajikistan, Thailand, Timor-Leste, Turkey, Turkmenistan, United Arab Emirates, Uzbekistan, Vietnam, Yemen.
Cupro Nickel 70/30 Nuts Supplier in Australia
Australia, Fiji, Kiribati, Marshall Islands, Micronesia, Nauru, New Zealand, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga, Tuvalu, Vanuatu.

Cupro Nickel 70/30 nuts offer a reliable solution for demanding marine and industrial environments where corrosion resistance and mechanical strength are non-negotiable. With controlled manufacturing processes and global export experience, KK Fasteners supports project-specific requirements with consistent quality and traceability.

For technical specifications, pricing, or custom requirements, connect with the engineering team to request a detailed quotation.

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