Nickel Alloy CY5SnBiM-SR (Stress relieved)
Heat-treated state
UNS N24135 · ASTM A494 CY5SnBiM
Optional anneal used on thick or intricate castings to relieve casting/machining stresses and homogenize the Sn-rich network before final machining; slightly softer with better ductility.
Values for the SR condition
Other CY5SnBiM tempers and conditions
CY5SnBiM is listed in 2 conditions; see the grade overview at CY5SnBiM.
- SR
- F
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Optional anneal used on thick or intricate castings to relieve casting/machining stresses and homogenize the Sn-rich network before final machining; slightly softer with better ductility. | 185 | 370 | 22 | 120 HB | 3.3 % IACS |
FDefault As fabricated | Standard supply condition for A494 CY5SnBiM sand and investment castings; no heat treatment, meets the specified tensile minima directly. | 200 | 390 | 18 | 130 HB | 3.2 % IACS |
What is CY5SnBiM-SR?
CY5SnBiM-SR is CY5SnBiM heat treated to SR — optional anneal used on thick or intricate castings to relieve casting/machining stresses and homogenize the Sn-rich network before final machining; slightly softer with better ductility. CY5SnBiM-SR has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 96% of nickel alloy grades. Elongation at break is 22% and the elastic modulus is 150 GPa (21.8 Msi). CY5SnBiM-SR has a density of 8.75 g/cm³ (0.316 lb/in³), heavier than 79% of nickel alloy grades. It melts at 1,290°C (2,354 °F). F is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Easy to machine — 58/100, better than 101% of nickel alloy grades
- High electrical conductivity — 3.3 % IACS, better than 90% of nickel alloy grades
- Conducts heat well — 21.5 W/m·K (12.4 BTU/hr·ft·°F), better than 89% of nickel alloy grades
- Low embodied carbon — 11 kg CO₂/kg, better than 85% of nickel alloy grades
Limitations
- Low strength — 185 MPa (26.8 ksi), worse than 96% of nickel alloy grades
- Low stiffness — 150 GPa (21.8 Msi), worse than 95% of nickel alloy grades
- Limited service temperature — 425°C (797 °F), worse than 90% of nickel alloy grades
- Limited formability — 12/100, worse than 83% of nickel alloy grades
- Difficult to weld — 28/100, worse than 79% of nickel alloy grades
CY5SnBiM-SR properties
Typical room-temperature values for CY5SnBiM-SR; 20 are specific to this condition. Other listed values are CY5SnBiM reference data and may not represent this condition. Bars are the position among nickel alloy grades.
Physical3
CY5SnBiM-SR has a density of 8.75 g/cm³ (0.316 lb/in³), heavier than 79% of nickel alloy grades. It melts at 1,290°C (2,354 °F).
Mechanical14
CY5SnBiM-SR has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 96% of nickel alloy grades. Elongation at break is 22% and the elastic modulus is 150 GPa (21.8 Msi).
Thermal6
CY5SnBiM-SR is rated for continuous service to 425°C (797 °F). It conducts heat at 21.5 W/m·K (12.4 BTU/hr·ft·°F), better than 89% of nickel alloy grades. Thermal expansion is 13.9 µm/m·K (7.72 µin/in·°F).
Electrical3
CY5SnBiM-SR conducts electricity at 3.3 % IACS, better than 90% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 67% of nickel alloy grades.
Sustainability4
Producing a kilogram of CY5SnBiM-SR takes about 110 MJ of energy and emits 11 kg of CO₂ — less than 93% of nickel alloy grades. Typical recycled content is 40%.
Manufacturability7
CY5SnBiM-SR's machinability is good (58/100, better than 101% of nickel alloy grades); weldability poor (28/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CY5SnBiM-SR
Is CY5SnBiM easy to machine?
The Sn/Bi phases break chips, so it turns and drills far more freely than M35-1 — use sharp positive-rake carbide, moderate speeds (~40–70 m/min) and heavy feeds to avoid work hardening.
Can CY5SnBiM be welded?
Weld repair is difficult and usually restricted: bismuth promotes hot cracking; if unavoidable, use low-heat-input GTAW with Ni-Cu (ERNiCu-7) filler after full excavation and preheat control.
Can CY5SnBiM be formed, bent or molded?
Sand or investment cast only; use generous gating/risering and controlled solidification to avoid Sn/Bi segregation and shrinkage porosity — the alloy is not hot- or cold-worked.
What surface finishes work on CY5SnBiM?
Machined surfaces polish well and can be electroless-nickel or chrome plated; no anodizing — passivation or simple pickling is used before seawater service.
CY5SnBiM 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 |
|---|---|---|
| Cu | 27 – 33 | 30 |
| Snmachinability addition; verify range against current ASTM A494 edition | 3.5 – 4.5 | 4 |
| Bilead-free chip-breaking addition; verify range against current ASTM A494 edition | 1 – 2 | 1.5 |
| C | ≤ 0.05 | 0.03 |
| Mn | ≤ 1.5 | 0.8 |
| Si | ≤ 1.25 | 0.8 |
| Fe | ≤ 2.5 | 1.2 |
| S | ≤ 0.02 | 0.01 |
| P | ≤ 0.03 | 0.01 |
| Niremainder, Ni + Co | ≥ 60 (balance) | — |
CY5SnBiM-SR — frequently asked
What is CY5SnBiM-SR used for?
CY5SnBiM-SR is typically used for ship propellers, marine pump impellers and seawater valve bodies. In short: free-machining cast Monel; seawater-resistant Ni-Cu casting; poor weld repairability.
What is the yield strength of CY5SnBiM-SR?
CY5SnBiM-SR has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 96% of nickel alloy grades. Strength varies by condition: see the 2 listed tempers.
Is CY5SnBiM-SR easy to machine?
Reasonably — machinability is rated good (58/100, better than 101% of nickel alloy grades). The Sn/Bi phases break chips, so it turns and drills far more freely than M35-1 — use sharp positive-rake carbide, moderate speeds (~40–70 m/min) and heavy feeds to avoid work hardening.
Can CY5SnBiM-SR be welded?
Not readily — weldability is rated poor (28/100). Weld repair is difficult and usually restricted: bismuth promotes hot cracking; if unavoidable, use low-heat-input GTAW with Ni-Cu (ERNiCu-7) filler after full excavation and preheat control.
What surface finishes work on CY5SnBiM-SR?
Machined surfaces polish well and can be electroless-nickel or chrome plated; no anodizing — passivation or simple pickling is used before seawater service.
Can CY5SnBiM-SR be formed, bent or molded?
Sand or investment cast only; use generous gating/risering and controlled solidification to avoid Sn/Bi segregation and shrinkage porosity — the alloy is not hot- or cold-worked.
What is the maximum service temperature of CY5SnBiM-SR?
CY5SnBiM-SR is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CY5SnBiM-F and CY5SnBiM-SR?
F is the default condition — standard supply condition for A494 CY5SnBiM sand and investment castings; no heat treatment, meets the specified tensile minima directly. SR: optional anneal used on thick or intricate castings to relieve casting/machining stresses and homogenize the Sn-rich network before final machining; slightly softer with better ductility. Yield strength is 200 MPa in F versus 185 MPa in SR.
Sources
- ASTM A494/A494M — Castings, Nickel and Nickel Alloy — ASTM International (2023)
- SAE/ASTM Unified Numbering System (UNS N24135) — SAE International / ASTM (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Nickel, Cobalt, and Their Alloys — ASM International (2000)
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.