Nickel Alloy M35-2-AC (Spheroidize annealed)
Heat-treated state · default condition
UNS J04020 · ASTM A494 M35-2
Default condition for pump casings, valve bodies and impellers; no heat treatment specified by A494.
Values for the AC condition
Other M35-2 tempers and conditions
M35-2 is listed in 3 conditions; see the grade overview at M35-2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Used to maximize ductility, homogenize dendritic segregation and improve corrosion uniformity before service in aggressive brines. | 210 | 470 | 37 | 118 HB | 3 % IACS |
Stress relieved | Choose when weld repairs or heavy machining have introduced residual stress, or to reduce distortion in thin-wall castings. | 220 | 480 | 34 | 125 HB | 3 % IACS |
ACDefaultThis page Spheroidize annealed | Default condition for pump casings, valve bodies and impellers; no heat treatment specified by A494. | 235 | 490 | 32 | 130 HB | 2.9 % IACS |
What is M35-2-AC?
M35-2-AC is M35-2 heat treated to AC — default condition for pump casings, valve bodies and impellers; no heat treatment specified by A494. M35-2-AC has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Elongation at break is 32% and the elastic modulus is 150 GPa (21.8 Msi). M35-2-AC has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 81% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Advantages
- Easy to machine — 35/100, better than 97% of nickel alloy grades
- Conducts heat well — 20 W/m·K (11.6 BTU/hr·ft·°F), better than 87% of nickel alloy grades
- High electrical conductivity — 2.9 % IACS, better than 86% of nickel alloy grades
Limitations
- Low stiffness — 150 GPa (21.8 Msi), worse than 95% of nickel alloy grades
- Low strength — 235 MPa (34.1 ksi), worse than 91% of nickel alloy grades
- Limited service temperature — 480°C (896 °F), worse than 82% of nickel alloy grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 75% of nickel alloy grades
- Limited formability — 20/100, worse than 75% of nickel alloy grades
M35-2-AC properties
Typical room-temperature values for M35-2-AC; 22 are specific to this condition. Other listed values are M35-2 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
M35-2-AC has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 81% of nickel alloy grades. It melts at 1,315°C (2,399 °F).
Mechanical16
M35-2-AC has a yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Elongation at break is 32% and the elastic modulus is 150 GPa (21.8 Msi).
Thermal6
M35-2-AC is rated for continuous service to 480°C (896 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), better than 87% of nickel alloy grades. Thermal expansion is 13.9 µm/m·K (7.72 µin/in·°F).
Electrical3
M35-2-AC conducts electricity at 2.9 % IACS, better than 86% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (75/100), worse than 63% of nickel alloy grades.
Sustainability4
Producing a kilogram of M35-2-AC takes about 150 MJ of energy and emits 12 kg of CO₂ — less than 68% of nickel alloy grades. Typical recycled content is 45%.
Manufacturability8
M35-2-AC's machinability is fair (35/100, better than 97% of nickel alloy grades); weldability very good (70/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with M35-2-AC
Is M35-2 easy to machine?
Gummy and work-hardening — use rigid setups, positive-rake carbide, heavy feeds at low speed (25–40 m/min) with flood coolant; the higher Si content helps chip breaking slightly versus M35-1.
Can M35-2 be welded?
Weld with ERNiCu-7/ENiCu-7 consumables using low heat input and no preheat; the higher Si/S limits of M35-2 make it more hot-crack prone than M35-1, so specify M35-1 where extensive weld repair is expected.
Can M35-2 be formed, bent or molded?
Sand or investment casting only — good fluidity from Si, but use generous risers and directional solidification because of the long freezing range and shrinkage tendency.
What surface finishes work on M35-2?
Pickle/passivate after machining, then polish or shot-blast; not anodizable — electroless nickel or PTFE coatings are used only where wear resistance is needed.
M35-2 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 |
|---|---|---|
| Cmax per ASTM A494 | ≤ 0.35 | 0.25 |
| Mn | ≤ 1.5 | 1 |
| Sihigher than M35-1 (1.25 max) for fluidity/strength | ≤ 2 | 1.6 |
| Cu | 26 – 33 | 30 |
| Fe | ≤ 3.5 | 2 |
| Nbcolumbium, max | ≤ 0.5 | — |
| Shigher allowance than M35-1 | ≤ 0.03 | — |
| Nibalance, approx. 63–70% | balance | — |
M35-2-AC — frequently asked
What is M35-2-AC used for?
M35-2-AC is typically used for pump and valve castings, marine hardware and chemical service fittings. In short: general-purpose cast Monel 400; better fluidity than M35-1; more hot-crack prone than M35-1.
What is the yield strength of M35-2-AC?
M35-2-AC has a typical yield strength of 235 MPa (34.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — weaker than 91% of nickel alloy grades. Strength varies by condition: see the 3 listed tempers.
Is M35-2-AC easy to machine?
Not especially — machinability is rated fair (35/100, better than 97% of nickel alloy grades). Gummy and work-hardening — use rigid setups, positive-rake carbide, heavy feeds at low speed (25–40 m/min) with flood coolant; the higher Si content helps chip breaking slightly versus M35-1.
Can M35-2-AC be welded?
Yes — weldability is rated very good (70/100). Weld with ERNiCu-7/ENiCu-7 consumables using low heat input and no preheat; the higher Si/S limits of M35-2 make it more hot-crack prone than M35-1, so specify M35-1 where extensive weld repair is expected.
What surface finishes work on M35-2-AC?
Pickle/passivate after machining, then polish or shot-blast; not anodizable — electroless nickel or PTFE coatings are used only where wear resistance is needed.
Can M35-2-AC be formed, bent or molded?
Sand or investment casting only — good fluidity from Si, but use generous risers and directional solidification because of the long freezing range and shrinkage tendency.
What is the maximum service temperature of M35-2-AC?
M35-2-AC is rated for continuous use to about 480°C (896 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between M35-2-AC and M35-2-ANN?
AC is the default condition — default condition for pump casings, valve bodies and impellers; no heat treatment specified by A494. ANN: used to maximize ductility, homogenize dendritic segregation and improve corrosion uniformity before service in aggressive brines. Yield strength is 235 MPa in AC versus 210 MPa in ANN.
Sources
- ASTM A494/A494M — Castings, Nickel and Nickel Alloy — ASTM International (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
- Monel alloy 400 technical bulletin — Special Metals Corporation (2005)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.