Nickel Alloy CW6M
UNS J30107, N10276 · ASTM A494 CW6M
CW6M (J30107, ASTM A494) is the cast version of Hastelloy C-276, a Ni-Cr-Mo alloy resistant to pitting, crevice corrosion and stress-corrosion cracking in highly oxidizing and reducing media.
Reference datasheet — CW6M is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SA condition
CW6M tempers and conditions
CW6M is supplied in 4 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed (≈1150–1180 °C, water quenched) per ASTM A494 | Standard supply condition for all corrosion-service castings; maximum ductility and corrosion resistance. | 310 | 550 | 40 | 185 HB | 1.4 % IACS |
weld repaired then re-solution annealed | Post-repair condition for foundry-corrected castings; restores homogeneous corrosion performance in the weld zone. | 310 | 540 | 35 | 185 HB | 1.4 % IACS |
hot isostatically pressed then solution annealed | Choose for pressure-containing or fatigue-loaded castings where microporosity must be closed (radiographic Level 1 parts). | 325 | 585 | 48 | 185 HB | 1.4 % IACS |
Spheroidize annealed | Only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition. | 330 | 500 | 12 | 205 HB | 1.3 % IACS |
What is CW6M?
CW6M (J30107, ASTM A494) is the cast version of Hastelloy C-276, a Ni-Cr-Mo alloy resistant to pitting, crevice corrosion and stress-corrosion cracking in highly oxidizing and reducing media. Solution-annealed castings give 310 MPa yield, 550 MPa tensile, 40 % elongation and 185 HB (90 HRB), a corrosion resistance score of 92 and service to 650 °C, normally as sand or investment castings for pump and valve bodies. Machinability scores 20 and the alloy is costly, so keep wall sections and machining allowances tight; CW2M is the alternative where strong oxidising acids are also present. CW6M has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 91% of nickel alloy grades. It melts at 1,325°C (2,417 °F). CW6M has a yield strength of 310 MPa (45 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 74% of nickel alloy grades. Elongation at break is 40% and the elastic modulus is 200 GPa (29 Msi).
What is CW6M used for?
- pump bodies for FGD systems
- chemical processing valves
- pulp and paper bleaching equipment
Advantages
- 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
CW6M properties
Typical room-temperature values for CW6M-SA; bars are the position among nickel alloy grades.
Physical3
CW6M has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 91% of nickel alloy grades. It melts at 1,325°C (2,417 °F).
Mechanical15
CW6M has a yield strength of 310 MPa (45 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 74% of nickel alloy grades. Elongation at break is 40% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
CW6M is rated for continuous service to 650°C (1,202 °F). It conducts heat at 10.2 W/m·K (5.89 BTU/hr·ft·°F), worse than 79% of nickel alloy grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
CW6M conducts electricity at 1.4 % IACS, worse than 65% of nickel alloy grades.
Chemical & Environmental3
Corrosion resistance is excellent (92/100), better than 91% of nickel alloy grades.
Sustainability4
Producing a kilogram of CW6M takes about 155 MJ of energy and emits 13.5 kg of CO₂ — less than 58% of nickel alloy grades. Typical recycled content is 45%.
Manufacturability7
CW6M's machinability is poor (20/100, better than 53% of nickel alloy grades); weldability very good (75/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the nickel alloy family
Yield strength against density for every nickel alloy grade FabDigit runs. CW6M is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CW6M
Is CW6M easy to machine?
Rigid setups, positive-rake carbide or ceramic-free coated inserts, low speed (15–25 m/min carbide) with heavy feed and flood coolant to cut under the work-hardened layer; never dwell.
Can CW6M be welded?
GTAW/GMAW with ERNiCrMo-4 (C-276) filler, low heat input, interpass <120 °C, no preheat; re-solution anneal after major repairs to restore corrosion resistance.
Can CW6M be formed, bent or molded?
Supplied as sand or investment castings — wide freezing range needs generous risering, chills and argon/vacuum melting to avoid microshrinkage and hot tears; not a wrought/cold-formed product.
CW6M 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 |
|---|---|---|
| Clow-carbon C-type grade | ≤ 0.07 | 0.03 |
| Mn | ≤ 1 | 0.6 |
| Si | ≤ 1 | 0.6 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 17 – 20 | 18.5 |
| Mo | 17 – 20 | 18.5 |
| Fe | ≤ 3 | 2 |
| W | ≤ 1 | 0.4 |
| Niremainder, ≈57–62 % | balance |
What surface finishes work on CW6M?
Grit-blast plus pickling in HNO₃-HF to remove the Cr-depleted casting skin, then passivate or electropolish; no anodizing, plating rarely needed.
Surface treatments FabDigit runs on nickel alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Nickel Alloy CW6M in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J30107N10276
- ASTM
- A494 CW6M
How much does CW6M cost?
CW6M is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
CW6M — frequently asked
What is CW6M used for?
CW6M is typically used for pump bodies for FGD systems, chemical processing valves and pulp and paper bleaching equipment. In short: cast C-276 standard; top pitting and crevice resistance; FGD industry default.
What is the yield strength of CW6M?
CW6M has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 74% of nickel alloy grades. Strength varies by condition: see the 4 listed tempers.
Is CW6M easy to machine?
Not especially — machinability is rated poor (20/100, better than 53% of nickel alloy grades). Rigid setups, positive-rake carbide or ceramic-free coated inserts, low speed (15–25 m/min carbide) with heavy feed and flood coolant to cut under the work-hardened layer; never dwell.
Can CW6M be welded?
Yes — weldability is rated very good (75/100). GTAW/GMAW with ERNiCrMo-4 (C-276) filler, low heat input, interpass <120 °C, no preheat; re-solution anneal after major repairs to restore corrosion resistance.
What surface finishes work on CW6M?
Grit-blast plus pickling in HNO₃-HF to remove the Cr-depleted casting skin, then passivate or electropolish; no anodizing, plating rarely needed.
Can CW6M be formed, bent or molded?
Supplied as sand or investment castings — wide freezing range needs generous risering, chills and argon/vacuum melting to avoid microshrinkage and hot tears; not a wrought/cold-formed product.
What is the maximum service temperature of CW6M?
CW6M is rated for continuous use to about 650°C (1,202 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CW6M-SA and CW6M-AC?
SA is the default condition — standard supply condition for all corrosion-service castings; maximum ductility and corrosion resistance. AC: only for non-corrosive structural or machining-stock use — interdendritic carbides/μ phase cut ductility and corrosion resistance; not an ASTM A494 delivery condition. Yield strength is 310 MPa in SA versus 330 MPa in AC.
How much does CW6M cost?
CW6M is a high-cost nickel alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A494/A494M — Castings, Nickel and Nickel Alloy — ASTM International (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (cast corrosion-resistant Ni alloys) — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- HASTELLOY C-276 alloy principal features and physical properties — Haynes International (2020)
- UNS N30107 alloy data — SAE/ASTM Metals & Alloys in the Unified Numbering System (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.