Nickel Alloy Alloy 242-SA (Solution annealed)
Heat-treated state · default condition
UNS N10242 · also Hastelloy 242
Standard supply condition for sheet, plate, bar and tube — softest, most formable and weldable state before ageing.
Values for the SA condition
Other Alloy 242 tempers and conditions
Alloy 242 is listed in 4 conditions; see the grade overview at Alloy 242.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefaultThis page Solution annealed | Standard supply condition for sheet, plate, bar and tube — softest, most formable and weldable state before ageing. | 375 | 805 | 48 | 215 HB | — |
As-welded deposit | Reference condition for weldment design when the joint is left in the annealed/as-deposited state. | 430 | 790 | 35 | 20 HRC | 1.4 % IACS |
Cold drawn | Use for small-diameter bar, wire and fasteners where higher as-supplied strength and close tolerance are needed without ageing. | 750 | 1,000 | 22 | 30 HRC | 1.4 % IACS |
SA + Aged | Pick for maximum strength and creep/fatigue capability in 400–815 °C service after all forming and welding are complete. | 850 | 1,210 | 21 | 34 HRC | — |
What is Alloy 242-SA?
Alloy 242-SA is Alloy 242 heat treated to SA — standard supply condition for sheet, plate, bar and tube — softest, most formable and weldable state before ageing. Alloy 242-SA has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 805 MPa (117 ksi) — weaker than 54% of nickel alloy grades. Elongation at break is 48% and the elastic modulus is 217 GPa (31.5 Msi). Alloy 242-SA has a density of 9.05 g/cm³ (0.327 lb/in³), heavier than 94% of nickel alloy grades. It melts at 1,320°C (2,408 °F).
Advantages
- Ductile — tolerates forming and impact — 48%, better than 83% of nickel alloy grades
Limitations
- Poor heat conductor — 9 W/m·K (5.2 BTU/hr·ft·°F), worse than 97% of nickel alloy grades
Alloy 242-SA properties
Typical room-temperature values for Alloy 242-SA; 12 are specific to this condition. Other listed values are Alloy 242 reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
Alloy 242-SA has a density of 9.05 g/cm³ (0.327 lb/in³), heavier than 94% of nickel alloy grades. It melts at 1,320°C (2,408 °F).
Mechanical13
Alloy 242-SA has a yield strength of 375 MPa (54.4 ksi) and a tensile strength of 805 MPa (117 ksi) — weaker than 54% of nickel alloy grades. Elongation at break is 48% and the elastic modulus is 217 GPa (31.5 Msi).
Thermal5
Alloy 242-SA is rated for continuous service to 815°C (1,499 °F). It conducts heat at 9 W/m·K (5.2 BTU/hr·ft·°F), worse than 97% of nickel alloy grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
Alloy 242-SA conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (80/100), better than 61% of nickel alloy grades.
Sustainability4
Producing a kilogram of Alloy 242-SA takes about 170 MJ of energy and emits 14 kg of CO₂ — more than 61% of nickel alloy grades. Typical recycled content is 30%.
Manufacturability8
Alloy 242-SA's machinability is poor (18/100, worse than 61% of nickel alloy grades); weldability good (60/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Alloy 242-SA
Is Alloy 242 easy to machine?
Machine like C-276/B-3: rigid setup, positive-rake carbide, low speed (15–25 m/min) with heavy positive feed and flood coolant to avoid work hardening; age-hardened stock is markedly harder and best ground or EDM'd.
Can Alloy 242 be welded?
GTAW/GMAW with matching 242 or Hastelloy-type filler, low heat input and interpass <100 °C, no preheat; weld in the solution-annealed condition and age afterwards for full strength.
Can Alloy 242 be formed, bent or molded?
Cold form only in the annealed state — high work-hardening rate demands intermediate anneals near 1065 °C with rapid quench; hot work 1180–950 °C.
What surface finishes work on Alloy 242?
Not anodizable; pickle/passivate after hot work to remove Mo-rich oxide, then abrasive-blast, electropolish or mechanically polish for a clean corrosion-resistant surface.
Alloy 242 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 |
|---|---|---|
| Mo | 24 – 26 | 25 |
| Cr | 7 – 9 | 8 |
| Fe | ≤ 2 | 1 |
| Co | ≤ 1 | 0.3 |
| Mn | ≤ 0.8 | 0.3 |
| Si | ≤ 0.8 | 0.2 |
| Al | ≤ 0.5 | 0.2 |
| Cu | ≤ 0.5 | 0.1 |
| C | ≤ 0.03 | 0.01 |
| B | ≤ 0.01 | 0 |
| Nibalance, typically ~62–66 % | balance | — |
Alloy 242-SA — frequently asked
What is Alloy 242-SA used for?
Alloy 242-SA is typically used for downhole tools, hydrofluoric acid alkylation units and aerospace fasteners. In short: age-hardenable Hastelloy grade; HF acid plus high strength; weld annealed, then age.
What is the yield strength of Alloy 242-SA?
Alloy 242-SA has a typical yield strength of 375 MPa (54.4 ksi) and a tensile strength of 805 MPa (117 ksi) — weaker than 54% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is Alloy 242-SA easy to machine?
Not especially — machinability is rated poor (18/100, worse than 61% of nickel alloy grades). Machine like C-276/B-3: rigid setup, positive-rake carbide, low speed (15–25 m/min) with heavy positive feed and flood coolant to avoid work hardening; age-hardened stock is markedly harder and best ground or EDM'd.
Can Alloy 242-SA be welded?
Yes — weldability is rated good (60/100). GTAW/GMAW with matching 242 or Hastelloy-type filler, low heat input and interpass <100 °C, no preheat; weld in the solution-annealed condition and age afterwards for full strength.
What surface finishes work on Alloy 242-SA?
Not anodizable; pickle/passivate after hot work to remove Mo-rich oxide, then abrasive-blast, electropolish or mechanically polish for a clean corrosion-resistant surface.
Can Alloy 242-SA be formed, bent or molded?
Cold form only in the annealed state — high work-hardening rate demands intermediate anneals near 1065 °C with rapid quench; hot work 1180–950 °C.
What is the maximum service temperature of Alloy 242-SA?
Alloy 242-SA is rated for continuous use to about 815°C (1,499 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Alloy 242-SA and Alloy 242 Aged?
SA is the default condition — standard supply condition for sheet, plate, bar and tube — softest, most formable and weldable state before ageing. Aged: pick for maximum strength and creep/fatigue capability in 400–815 °C service after all forming and welding are complete. Yield strength is 375 MPa in SA versus 850 MPa in Aged.
Sources
- HAYNES 242 alloy technical brochure (H-3021) — Haynes International (2020)
- ASTM B622 / B619 / B626 — Ni-Mo-Cr alloy tube and pipe (UNS N10242) — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- AMS 5896 / SAE nickel alloy sheet, strip and plate specifications — SAE International (2019)
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.