C715 Cupro-Nickel is a 70/30 copper nickel alloy that is almost entirely resistant to stress corrosion. The addition of small amounts of iron and manganese make 70-30 CuNi ideal for use in applications involving high-velocity polluted seawater. Typical 715 CuNi applications for use in the chemical and desalination industries include tubes and tubesheets for condensers, evaporators and heat exchangers; tubes for carrying seawater; valve bodies; pump bodies and impellers. C71500 70-30 Copper-Nickel is known for its strength, workability, formability and weldability.
Marmetal stocks 715 70/30 Copper Nickel in Sheet, Plate, Bar, Pipe and Condenser Tube form, as well as Flanges, Fittings, Forgings and Castings.
| ASTM | ASME | Military | |
| Bar | ASTM B151 | ASME SB-151 | MIL-C-15726 |
| Forging | MIL-C-24679 | ||
| Sheet | ASTM B171 | ASME SB-171 | MIL-C-15726 |
| Plate | ASTM B171 | ASME SB-171 | MIL-C-15726 |
| Pipe | ASTM B466 | ASME SB-466 | MIL-T-16420 |
| Tube | ASTM B111 | ASME SB-111 | MIL-T-15005 |
| BAR – Round, Hex and Square | |||||
| Commercial | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O60 | up to 1/2″ | 52 | 18 | 30 | |
| over 1/2″ to 1″ | 48 | 18 | 30 | ||
| over 1″ | 45 | 18 | 30 | ||
| H01 | up to 1/2″ | 65 | 50 | 10 | |
| over 1/2″ to 1″ | 60 | 45 | 15 | ||
| over 1″ to 3″ | 55 | 35 | 20 | ||
| over 3″ to 5″ | 45 | 18 | 20 | ||
| MIL-C-15726 | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O60 | All Sizes | 45 | 18 | 30 | |
| H01 | up to 1/2″ | 65 | 50 | 10 | |
| over 1/2″ to 1″ | 60 | 45 | 15 | ||
| over 1″ to 3″ | 55 | 35 | 20 | ||
| SHEET/PLATE | |||||
| Commercial | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| M20 / O25 | up to 2-1/2″ | 50 | 20 | 30 | |
| over 2-1/2″ | 45 | 18 | 30 | ||
| MIL-C-15726 | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O60 | up to 3/16″ | 50 | 20 | 30 | |
| M20 Soft | over 3/16″ to 2-1/2″ | 50 | 20 | 30 | |
| M20 Soft | over 2-1/2″ | 45 | 18 | 35 | |
| H01 | up to 3/16″ x 24″ wide | 60 | 30 | 10 | |
| H01 | up to 3/16″ x over 24″ wide | 55 | 25 | 10 | |
| M20 Hard | up to 1/2″ x over 24″ wide | 50 | 22 | 15 | |
| M20 Hard | over 1/2″ x all widths | 45 | 18 | 20 | |
| PIPE | |||||
| Commercial | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O60 | All Sizes | 52 | 18 | N/A | |
| H80 | All Sizes | 70 | 45 | N/A | |
| MIL-T-16420 | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O60 | up to 4-1/2″ | 50 | 18 | 30 | |
| over 4-1/2″ | 50 | 16 | 30 | ||
| TUBE | |||||
| Commercial | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O61 | All Sizes | 52 | 18 | N/A | |
| MIL-T-15005 | |||||
| TEMPER | SIZE | TENSILE, KSI, MIN | YIELD@0.5%, KSI, MIN | Elong. % Min | |
| O61 | All Sizes | 52 | 18 | N/A |
COMMERCIAL
| UNS No. | Copper + Silver | Nickel + Cobalt | Manganese | Lead | Iron | Zinc | Phosphorus | Sulfur | Carbon |
| C71500 | remainder | 29.0-33.0 | 1.0 max | 0.05a max | 0.40-1.0 | 1.0a | |||
| C71520 | 65.0 min | 29.0-33.0 | 1.0 max | 0.02 | 0.40-1.0 | 0.5 | 0.02 max | 0.02 max | 0.05 max |
aFor subsequent welding application, max levels are: Zinc 0.50, Lead 0.02, Phosphorus 0.02, Sulfur 0.02, Carbon 0.05
MIL-C-15726
| UNS No. | Copper | Nickel + Cobalt | Manganese | Lead | Iron | Zinc | Phosphorus | Sulfur | Carbon | Cu + plus elements with specific limits, min |
| C71500 | 65.0 min | 29.0-33.0 | 1.0 max | 0.02 max | 0.40-1.0 | 0.50 max | 0.02 max | 0.02 max | 0.05 max | 99.5 |
MIL-T-16420
| UNS No. | Copper + Silver | Nickel + Cobalt | Manganese | Lead | Iron | Zinc | Phosphorus | Sulfur | Carbon | Cu + plus elements with specific limits, min |
| C71500 | 65.0 min | 29.0-33.0 | 1.0 max | 0.02 max | 0.40-1.0 | 0.50 max | 0.02 max | 0.02 max | 0.05 max | 99.5 |
MIL-T-15005
| UNS No. | Copper + Silver | Nickel + Cobalt | Manganese | Lead | Iron | Zinc | Phosphorus | Sulfur | Carbon |
| C71500 | remainder | 29.0-33.0 | 1.0 max | 0.02 max | 0.40-1.0 | 0.50 max | 0.02 max | 0.02 max | 0.05 max |
| Density @ 68o F | 0.323 lb/in3 |
| Melting Range | 2140-2265o F |
| Hot Formability | Good |
| Cold Formability | Good |
| Machinability rating (C360 = 100) | 20 |
| Brazing | Excellent |
| Soldering | Excellent |
| Gas-shielded arc welding | Excellent |
| Oxy-acetylene welding | Good |
| Carbon-arc welding | Not recommended |
| Coated metal-arc welding | Good |
| Resistant welding: spot and seam | Good |
| Resistance Welding: butt | Good |
| * Condensers |
| * Evaporators |
| * Tubesheets |
| * Valve Bodies |
| * Pump Bodies |
| * Impellers |
| * Fire Supression Systems |
| * Brake Lines |
| * Heat Exchangers |
| * Fasteners |
| * Fittings |
| * Flanges |