Tesco Steel & Engineering manufactures UNS C70600 copper nickel flanges — the 90/10 Cu-Ni alloy (CuNi10Fe1Mn, DIN 2.0872, EN CW352H), the most widely used marine copper-nickel grade. With ~88.5% copper, 10% nickel and controlled iron and manganese, C70600 delivers outstanding seawater corrosion resistance, strong resistance to chloride stress-corrosion cracking, and natural antifouling behaviour that keeps piping clear of marine growth. Available in weld neck, slip-on, blind, socket-weld, threaded and lap-joint types to ASME B16.5 / B16.47 and marine standards EEMUA 145 / DIN 86019. Class 150 to 2500, NPS 1/2″ to 24″, PN6 to PN400. ISO 9001:2015 certified. Made in India.
UNS C70600 (90/10) Copper Nickel Flanges
Copper Nickel Weld Neck & Blind Flanges
Tesco Steel & Engineering manufactures C70600 copper nickel flanges in all types from weld neck to blind, Class 150 to 2500 — supplied with EN 10204 3.1 / 3.2 certification, PMI and third-party inspection on request. Explore the wider copper nickel flange range, 90/10 copper nickel flanges, UNS C71500 (70/30) copper nickel flanges, and the flange dimension charts.
| UNS C70600 (90/10) copper nickel flanges are available in the following specifications: | |
|---|---|
| Material Grade | UNS C70600 / 90/10 Cu-Ni / CuNi10Fe1Mn / DIN 2.0872 / EN CW352H |
| Alloy Type | Copper-nickel (~88.5% Cu, 10% Ni + Fe, Mn) — marine grade |
| Size | 1/2″ NB to 24″ NB (DN 15 to DN 600); larger to ASME B16.47 |
| Class / Rating | 150#, 300#, 600#, 900#, 1500#, 2500# · 3000#, 6000#, 9000# (socket-weld / threaded) |
| Pressure Ratings | PN 6 – PN 400 (PN6, 10, 16, 25, 40, 64, 100, 160, 250, 320, 400) |
| Material Standards | ASTM B151 (rod), B171 (plate), B466 (pipe); EEMUA 145; DIN 86019 |
| Dimensional Standards | ASME B16.5, ASME B16.47 (Series A & B), MSS SP-44, DIN EN 1092-1 |
| Flange Types | Weld Neck (WNRF), Slip-On (SORF), Blind, Socket Weld (SWRF), Lap Joint, Threaded / Screwed, Plate, Long Weld Neck, Orifice |
| Flange Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Tongue & Groove (T&G) |
| Weld Filler | ERCuNi (AWS A5.7) |
| Testing | PMI, hydrostatic, UT, MT/PT per spec; EN 10204 3.1 / 3.2 |
90/10 copper nickel is a copper-rich alloy with 10% nickel and deliberate iron and manganese additions. The iron and manganese are critical — they strengthen the protective surface film and markedly improve resistance to impingement and erosion-corrosion in flowing seawater.
| Element | UNS C70600 (90/10 Cu-Ni) |
|---|---|
| Copper (Cu) | Balance (~86–88%) |
| Nickel (Ni) | 9.0 – 11.0% |
| Iron (Fe) | 1.0 – 1.8% (impingement resistance) |
| Manganese (Mn) | 0.5 – 1.0% |
| Zinc (Zn) | 1.0% max |
| Lead (Pb) | 0.05% max |
| Mechanical Property (annealed, typical) | UNS C70600 |
|---|---|
| Tensile Strength | 275 – 330 MPa (40–48 ksi) |
| Yield Strength 0.2% | 105 – 140 MPa (15–20 ksi) |
| Elongation | ~30% |
| Density | 8.90 g/cm³ |
| Max Service Temperature | ~300–350 °C |
| Max Seawater Velocity (pipe) | ~3.0–3.5 m/s |
| Standard | C70600 (90/10) Designation |
|---|---|
| UNS (USA) | C70600 |
| EN (Europe) | CW352H (CuNi10Fe1Mn) |
| DIN / Werkstoff | 2.0872 (CuNi10Fe1Mn) |
| BS (UK) | CN102 |
| ASTM material | B151 (rod), B171 (plate), B466 (pipe) |
| Common name | 90/10 Copper Nickel (Cu-Ni) |
C70600 Long Weld Neck Flange
C70600 Slip-On Flange (SORF)
C70600 Socket Weld Flange (SWRF)
| Flange Type | Description & C70600-Specific Use |
|---|---|
| Weld Neck (WNRF) | Tapered hub butt-welded to pipe for high-integrity seawater lines; weld with ERCuNi filler, no PWHT. |
| Slip-On (SORF) | Fillet-welded over the pipe; the most common copper-nickel connection for shipboard and marine piping. |
| Blind (BFF) | Seals pipe ends and vessel nozzles in seawater and firewater systems. |
| Socket Weld (SWRF) | Small-bore (1/2″–2″) instrument and branch connections in seawater service. |
| Lap Joint (LJRF) | Used with a Cu-Ni stub end where frequent dismantling is needed; economises on alloy in the backing ring. |
| Threaded (TRFF) | Internal NPT/BSP threads for non-welded connections in low-pressure seawater utility service. |
| Long Weld Neck / Orifice / Plate | Nozzle, flow-metering and plate flanges in C70600 for marine and desalination duty. |
| Property | 90/10 (C70600) | 70/30 (C71500) | C71640 (66/30/2/2) |
|---|---|---|---|
| Nickel content | ~10% | ~30% | ~30% (Fe/Mn enhanced) |
| Seawater corrosion / antifouling | Excellent | Excellent | Excellent |
| Strength | Moderate | Higher | Higher |
| Max seawater velocity | ~3.0–3.5 m/s | ~4.0–4.5 m/s | Highest (sand-laden) |
| Elevated-temperature service | Good | Better | Better |
| Relative cost | Lowest | Higher (more Ni) | Higher |
| Best For | General seawater piping, shipboard, desalination | Higher-velocity / higher-strength / hotter service | Sand-laden, high-velocity seawater (e.g. intakes) |
Excellent general, pitting and crevice resistance plus high resistance to chloride stress-corrosion cracking — the marine standard.
Copper content inhibits settlement of barnacles, mussels and algae — keeps pipe bores clear without coatings or biocides.
Readily welded with ERCuNi filler, no preheat or PWHT — straightforward marine fabrication.
Lowest-cost copper-nickel grade for general seawater service where 70/30's extra strength/velocity tolerance isn't required.
| Industry | Typical Application |
|---|---|
| Shipbuilding & Naval | Seawater cooling, ballast, bilge, firewater and sanitary seawater piping |
| Offshore Platforms | Seawater and firewater ring mains, cooling-water systems |
| Desalination | Seawater intake, MSF/RO cooling and brine-handling piping |
| Power Generation | Seawater-cooled condenser and cooling-water circuit flanges |
| Coastal HVAC & Process | Seawater cooling for chillers and process exchangers |
| Heat Exchangers | Tube-sheet and nozzle flanges in seawater-cooled exchangers |
Made from certified 90/10 copper-nickel with PMI verification of Ni, Fe and Mn — full chemistry on the MTC.
Manufactured to ASME B16.5 with EEMUA 145 / DIN 86019 compliance for shipbuilding and offshore.
WNRF, SORF, blind, socket-weld, threaded, lap-joint, LWN, orifice and plate — in RF, FF, RTJ and T&G faces.
EN 10204 3.1 / 3.2 MTC, heat/lot traceability, hydrostatic and third-party inspection on request.
C70600 (90/10) flange prices track copper and nickel market rates plus size, pressure class, flange type and quantity — 90/10 is the most economical copper-nickel grade. Tesco Steel & Engineering offers competitive ex-works pricing from Mumbai with full export documentation and material traceability. Click Ask for Quote or message us on WhatsApp at +91 92233 66922 with flange type, size (NB), pressure class, quantity and documentation requirements.
Q1. What is a UNS C70600 copper nickel flange?
A UNS C70600 copper nickel flange is a pipe flange made from 90/10 copper-nickel alloy (about 88.5% copper, 10% nickel, plus iron and manganese), also designated CuNi10Fe1Mn, DIN 2.0872 and EN CW352H. It is the most widely used marine copper-nickel grade, valued for outstanding resistance to seawater corrosion and marine biofouling. Flanges are machined to ASME B16.5 / B16.47 dimensions and supplied to marine standards such as EEMUA 145 and DIN 86019.
Q2. What is the difference between 90/10 (C70600) and 70/30 (C71500) copper nickel?
Both are copper-nickel alloys with the same excellent seawater corrosion and biofouling resistance. 90/10 (C70600) has 10% nickel and is the most economical, general-purpose marine grade, used for typical seawater piping velocities. 70/30 (C71500) has 30% nickel, giving higher strength, higher tolerance of seawater flow velocity and better resistance at elevated temperature. 90/10 is the default for most shipboard and desalination piping; 70/30 where the duty is more severe.
Q3. What is the chemical composition of C70600 copper nickel?
UNS C70600 (90/10 Cu-Ni) composition: nickel 9.0–11.0%, iron 1.0–1.8%, manganese 0.5–1.0%, copper balance (~86–88%), with limits on zinc, lead and other residuals. The controlled iron and manganese additions are important — they significantly improve resistance to impingement attack and erosion-corrosion in flowing seawater.
Q4. Why is C70600 copper nickel used in seawater service?
C70600 forms a protective surface film in seawater that gives excellent resistance to general corrosion, pitting and crevice corrosion, plus strong resistance to chloride stress-corrosion cracking. Critically, copper-nickel is naturally antifouling — its copper content inhibits the settlement of marine organisms (barnacles, mussels, algae), keeping piping bores clear without coatings or biocides. This makes 90/10 Cu-Ni the standard for shipboard seawater systems, desalination and offshore cooling water.
Q5. What standards apply to C70600 copper nickel flanges?
C70600 copper nickel flanges are made to ASME B16.5 / B16.47 dimensional standards in material to ASTM B151 (rod), ASTM B171 (plate) and ASTM B466 (pipe), and to marine fabrication standards EEMUA 145 and DIN 86019. Equivalents are CuNi10Fe1Mn, DIN/Werkstoff 2.0872 and EN CW352H. Certification is supplied per EN 10204 3.1 / 3.2.
Q6. What are the mechanical properties of C70600 copper nickel?
Typical 90/10 copper nickel (C70600) properties in the annealed condition: tensile strength about 275–330 MPa, yield strength about 105–140 MPa, elongation about 30%, density 8.9 g/cm³. It is a moderate-strength, highly ductile alloy used primarily for corrosion resistance rather than strength; where higher strength is needed, 70/30 (C71500) is selected.
Q7. Can C70600 copper nickel flanges be welded?
Yes. C70600 is readily welded by GTAW (TIG) and GMAW using matching copper-nickel filler such as ERCuNi (AWS A5.7). No preheat or post-weld heat treatment is required. Joints should be clean and the alloy welded with controlled heat input; copper-nickel has higher thermal conductivity than steel, so technique differs slightly, but it is considered easy to weld for marine fabrication.
Q8. What is the maximum seawater flow velocity for 90/10 copper nickel?
90/10 copper nickel (C70600) is generally limited to a maximum continuous seawater velocity of about 3.0–3.5 m/s in pipework to avoid impingement attack and erosion-corrosion of the protective film. Where higher velocities are unavoidable, 70/30 (C71500) — which tolerates up to about 4.0–4.5 m/s — is specified. Correct sizing to keep velocity within limits is key to long copper-nickel service life.
Q9. What industries use C70600 copper nickel flanges?
C70600 (90/10) copper nickel flanges are used in shipbuilding and naval seawater systems (cooling, ballast, firewater, bilge), offshore platforms (seawater and firewater ring mains), desalination plants, power-station seawater condenser and cooling-water circuits, and coastal/marine HVAC and process cooling — wherever seawater corrosion and biofouling resistance are required.
Q10. Are C70600 copper nickel flanges supplied with material test certificates?
Yes. Every C70600 copper nickel flange is supplied with EN 10204 3.1 (or 3.2) mill test certificates confirming chemistry, mechanical properties and heat/lot traceability, with PMI, hydrostatic testing and third-party inspection on request. Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer and exporter from Mumbai, India.