Nickel Alloy MP35N-CW20
Supply condition
UNS R30035 · EN 2.4999
CW20 = cold Worked ~20 %
Intermediate strength with retained ductility for formed springs, tubing and medical wire that must still be bent or coiled.
Values for the CW20 condition
Other MP35N tempers and conditions
MP35N is listed in 7 conditions; see the grade overview at MP35N.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for deep drawing, wire redrawing, machining of complex parts and for weld fabrication before final strengthening. | 415 | 950 | 65 | 210 HB | — |
Hot Worked + Aged | Used when the section is too large to cold work; gives moderate aged strength with good toughness in forgings and thick bar. | 830 | 1,240 | 25 | 36 HRC | 1.7 % IACS |
CW20This page Cold Worked ~20 % | Intermediate strength with retained ductility for formed springs, tubing and medical wire that must still be bent or coiled. | 900 | 1,240 | 35 | 34 HRC | 1.7 % IACS |
Cold Worked ~50 % | High-strength unaged condition for fine wire, cables and springs where aging distortion is unacceptable. | 1,590 | 1,720 | 12 | 46 HRC | — |
CW-AGED-260Default Cold Worked + Aged, 260 ksi class | Standard aerospace fastener and downhole bar condition — 1793 MPa minimum UTS with good ductility and full corrosion resistance. | 1,790 | 1,930 | 10 | 50 HRC | — |
Cold Worked + Aged, 285 ksi class | Higher cold-work level for small-diameter fasteners and springs needing ~1965 MPa minimum tensile with reduced ductility. | 1,930 | 2,030 | 8 | 53 HRC | 1.7 % IACS |
Cold Worked + Aged, 300 ksi class | Maximum-strength condition obtainable only in wire and small-diameter bar; choose for the highest fastener preload or spring stress. | 2,000 | 2,100 | 6 | 55 HRC | 1.7 % IACS |
What is MP35N-CW20?
MP35N-CW20 is MP35N supplied in the CW20 condition — intermediate strength with retained ductility for formed springs, tubing and medical wire that must still be bent or coiled. MP35N-CW20 has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 94% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 228 GPa (33.1 Msi). MP35N-CW20 has a density of 8.43 g/cm³ (0.305 lb/in³), heavier than 59% of nickel alloy grades. It melts at 1,315°C (2,399 °F). CW-AGED-260 is the default condition FabDigit quotes; CW20 is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 88/100, better than 100% of nickel alloy grades
- High strength — 900 MPa (131 ksi), better than 94% of nickel alloy grades
- Good corrosion resistance — 92/100, better than 91% of nickel alloy grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 85% of nickel alloy grades
- High electrical conductivity — 1.7 % IACS, better than 76% of nickel alloy grades
Limitations
- Limited service temperature — 370°C (698 °F), worse than 96% of nickel alloy grades
- High embodied carbon — 16 kg CO₂/kg, worse than 93% of nickel alloy grades
MP35N-CW20 properties
Typical room-temperature values for MP35N-CW20; 23 are specific to this condition. Other listed values are MP35N reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
MP35N-CW20 has a density of 8.43 g/cm³ (0.305 lb/in³), heavier than 59% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical16
MP35N-CW20 has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 94% of nickel alloy grades. Elongation at break is 35% and the elastic modulus is 228 GPa (33.1 Msi).
Thermal5
MP35N-CW20 is rated for continuous service to 370°C (698 °F). It conducts heat at 11.2 W/m·K (6.47 BTU/hr·ft·°F), worse than 52% of nickel alloy grades. Thermal expansion is 12.8 µm/m·K (7.11 µin/in·°F).
Electrical3
MP35N-CW20 conducts electricity at 1.7 % IACS, better than 76% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 91% of nickel alloy grades.
Sustainability4
Producing a kilogram of MP35N-CW20 takes about 230 MJ of energy and emits 16 kg of CO₂ — more than 91% of nickel alloy grades. Typical recycled content is 20%.
Manufacturability8
MP35N-CW20's machinability is poor (16/100, worse than 71% of nickel alloy grades); weldability fair (40/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MP35N-CW20
Is MP35N easy to machine?
Very difficult — extreme work hardening and low thermal conductivity; use rigid setups, positive-rake carbide or ceramic tooling, heavy positive feed with no dwell, low surface speed and copious high-pressure coolant.
Can MP35N be welded?
GTAW/plasma/EB/laser welding is feasible in the annealed condition with matching filler; welding after cold work and aging destroys the strengthening in the HAZ and is generally avoided.
Can MP35N be formed, bent or molded?
Excellent cold formability when annealed (drawing, coiling, heading with interstage anneals); in the cold-worked + aged condition it is essentially unformable, so all bending must precede aging.
What surface finishes work on MP35N?
Not anodizable; finish by electropolishing or passivation for corrosion and implant surfaces, and use dry-film or MoS2 lubricants / silver plating on threaded fasteners to prevent galling.
MP35N chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ni | 33 – 37 | 35 |
| Cr | 19 – 21 | 20 |
| Mo | 9 – 10.5 | 10 |
| Fe | ≤ 1 | 0.5 |
| Tiaids age hardening | ≤ 1 | 0.5 |
| Mn | ≤ 0.15 | — |
| Si | ≤ 0.15 | — |
| C | ≤ 0.03 | — |
| P | ≤ 0.02 | — |
| S | ≤ 0.01 | — |
| B | ≤ 0.02 | — |
| Cobalance in most specifications | ≥ 33 (balance) | — |
MP35N-CW20 — frequently asked
What is MP35N-CW20 used for?
MP35N-CW20 is typically used for aerospace fasteners, high-strength springs, surgical implants, cardiovascular stents and wire rope/cable. In short: highest-strength implant alloy; cold-work plus age strengthened; poor machinability, high cost.
What is the yield strength of MP35N-CW20?
MP35N-CW20 has a typical yield strength of 900 MPa (131 ksi) and a tensile strength of 1,240 MPa (180 ksi) — stronger than 94% of nickel alloy grades. Strength varies by condition: see the 7 listed tempers.
Is MP35N-CW20 easy to machine?
Not especially — machinability is rated poor (16/100, worse than 71% of nickel alloy grades). Very difficult — extreme work hardening and low thermal conductivity; use rigid setups, positive-rake carbide or ceramic tooling, heavy positive feed with no dwell, low surface speed and copious high-pressure coolant.
Can MP35N-CW20 be welded?
With care — weldability is rated fair (40/100). GTAW/plasma/EB/laser welding is feasible in the annealed condition with matching filler; welding after cold work and aging destroys the strengthening in the HAZ and is generally avoided.
What surface finishes work on MP35N-CW20?
Not anodizable; finish by electropolishing or passivation for corrosion and implant surfaces, and use dry-film or MoS2 lubricants / silver plating on threaded fasteners to prevent galling.
Can MP35N-CW20 be formed, bent or molded?
Excellent cold formability when annealed (drawing, coiling, heading with interstage anneals); in the cold-worked + aged condition it is essentially unformable, so all bending must precede aging.
What is the maximum service temperature of MP35N-CW20?
MP35N-CW20 is rated for continuous use to about 370°C (698 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between MP35N CW-AGED-260 and MP35N-ANN?
CW-AGED-260 is the default condition — standard aerospace fastener and downhole bar condition — 1793 MPa minimum UTS with good ductility and full corrosion resistance. ANN: softest condition for deep drawing, wire redrawing, machining of complex parts and for weld fabrication before final strengthening. Yield strength is 1,790 MPa in CW-AGED-260 versus 415 MPa in ANN.
Sources
- AMS 5844 — Alloy Bars, Forgings and Tubing 35Co-35Ni-20Cr-10Mo, Work Strengthened and Aged — SAE International (2018)
- ASTM F562 — Wrought 35Cobalt-35Nickel-20Chromium-10Molybdenum Alloy for Surgical Implants — ASTM International (2022)
- ASTM F688 — Wrought Cobalt-35Nickel-20Chromium-10Molybdenum Alloy Plate, Sheet and Foil — ASTM International (2021)
- MP35N Multiphase Alloy technical data — Carpenter Technology / SPS Technologies (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- NACE MR0175 / ISO 15156-3 — Materials for use in H2S-containing environments — NACE/ISO (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.