Stainless Steel CB7Cu-2
UNS J92110 · ASTM A747 Grade CB7Cu-2
A cast martensitic precipitation-hardening stainless steel closely related to CB7Cu-1 but with lower nickel and higher copper content, corresponding to wrought 15-5PH (S15500); valued for high strength, good toughness, and corrosion resistance in aerospace and industrial castings.
Reference datasheet — CB7Cu-2 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 H1100 condition
CB7Cu-2 tempers and conditions
CB7Cu-2 is supplied in 8 conditions, soft to hard. H1100 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Double overaged 760 °C + 621 °C | Specify where maximum notch toughness and low hardness (e.g. sour-service or cryogenic-tolerant parts) outweigh strength. | 550 | 790 | 20 | 25 HRC | — |
Solution annealed | As-supplied condition from the foundry for machining and subsequent single-step aging; not normally used in service. | 725 | 930 | 12 | 32 HRC | — |
Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Pick for maximum toughness, ductility and best SCC/H₂ embrittlement resistance at the lowest strength level. | 760 | 900 | 16 | 30 HRC | — |
H1100Default Aged 593 °C (1100 °F) for 4 h | Most commonly stocked casting condition — good compromise of strength, toughness and corrosion resistance. | 860 | 1,000 | 13 | 33 HRC | — |
Aged 579 °C (1075 °F) for 4 h | Use when moderate strength with good impact toughness and easier machining is wanted. | 930 | 1,035 | 12 | 35 HRC | — |
Aged 552 °C (1025 °F) for 4 h | Balanced condition: ~1070 MPa tensile with clearly improved ductility over H900. | 1,035 | 1,105 | 11 | 38 HRC | — |
Aged 496 °C (925 °F) for 4 h | Slightly overaged from H900 for a small gain in toughness and SCC resistance at near-peak strength. | 1,140 | 1,240 | 10 | 42 HRC | — |
Aged 482 °C (900 °F) for 1 h, peak hardness | Choose for maximum strength and hardness where toughness and SCC resistance are secondary. | 1,210 | 1,350 | 8 | 44 HRC | — |
What is CB7Cu-2?
A cast martensitic precipitation-hardening stainless steel closely related to CB7Cu-1 but with lower nickel and higher copper content, corresponding to wrought 15-5PH (S15500); valued for high strength, good toughness, and corrosion resistance in aerospace and industrial castings. CB7Cu-2 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F). CB7Cu-2 has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 196 GPa (28.4 Msi).
What is CB7Cu-2 used for?
- aerospace structural castings
- pump and valve components
- high-strength fasteners
- turbine parts
- food and chemical processing equipment
Advantages
- High strength — 860 MPa (125 ksi), better than 98% of stainless steel grades
Limitations
- Limited ductility — 13%, worse than 93% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Limited formability — 20/100, worse than 86% of stainless steel grades
CB7Cu-2 properties
Typical room-temperature values for CB7Cu-2-H1100; bars are the position among stainless steel grades.
Physical3
CB7Cu-2 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
CB7Cu-2 has a yield strength of 860 MPa (125 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 13% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
CB7Cu-2 is rated for continuous service to 300°C (572 °F). It conducts heat at 17.8 W/m·K (10.3 BTU/hr·ft·°F), better than 72% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
CB7Cu-2 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 62% of stainless steel grades.
Sustainability4
Producing a kilogram of CB7Cu-2 takes about 55 MJ of energy and emits 4.2 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
CB7Cu-2's machinability is fair (42/100, better than 79% of stainless steel grades); weldability good (65/100); formability poor (20/100).
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 stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. CB7Cu-2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CB7Cu-2
Is CB7Cu-2 easy to machine?
Machine in Condition A or after H1075–H1150 aging; rigid setups, sharp carbide with positive rake, 30–60 m/min, heavy feed to cut under the work-hardened skin — H900 parts should only be finish-ground.
Can CB7Cu-2 be welded?
Readily GTAW/GMAW welded with matching 15-5PH or 17-4PH (AMS 5826) filler, low heat input, no preheat needed; re-solution-treat and re-age (or at minimum re-age) for full properties in the weld and HAZ.
Can CB7Cu-2 be formed, bent or molded?
Sand or investment cast with generous risering and chills to avoid shrinkage porosity; HIP is common for aerospace castings, then solution treat ~1040 °C, air/oil quench and single-step age.
CB7Cu-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 |
|---|---|---|
| C | ≤ 0.07 | 0.05 |
| Mn | ≤ 0.7 | 0.5 |
| Si | ≤ 1 | 0.6 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cr | 14 – 15.5 | 14.8 |
| Ni | 4.5 – 5.5 | 5 |
| Cuprecipitation hardener (ε-Cu) | 2.5 – 3.2 | 2.9 |
| NbCb (+Ta) stabilizer | 0.15 – 0.35 | 0.25 |
| Fe | balance |
What surface finishes work on CB7Cu-2?
Passivate per ASTM A967 (nitric or citric) after machining; electropolish or fine-polish for hygienic surfaces; can be chrome-plated or nitrided if baked below the aging temperature to avoid hydrogen embrittlement — anodizing is not applicable.
Surface treatments FabDigit runs on stainless steel 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).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel CB7Cu-2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J92110
- ASTM
- A747 Grade CB7Cu-2
- Also called
- Cast 15-5PH
- Similar grades
- S15500
How much does CB7Cu-2 cost?
CB7Cu-2 is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
CB7Cu-2 — frequently asked
What is CB7Cu-2 used for?
CB7Cu-2 is typically used for aerospace structural castings, pump and valve components, high-strength fasteners, turbine parts and food and chemical processing equipment. In short: cast 15-5PH equivalent; strongest cast PH stainless; aerospace casting grade.
What is the yield strength of CB7Cu-2?
CB7Cu-2 has a typical yield strength of 860 MPa (125 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is CB7Cu-2 easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine in Condition A or after H1075–H1150 aging; rigid setups, sharp carbide with positive rake, 30–60 m/min, heavy feed to cut under the work-hardened skin — H900 parts should only be finish-ground.
Can CB7Cu-2 be welded?
Yes — weldability is rated good (65/100). Readily GTAW/GMAW welded with matching 15-5PH or 17-4PH (AMS 5826) filler, low heat input, no preheat needed; re-solution-treat and re-age (or at minimum re-age) for full properties in the weld and HAZ.
What surface finishes work on CB7Cu-2?
Passivate per ASTM A967 (nitric or citric) after machining; electropolish or fine-polish for hygienic surfaces; can be chrome-plated or nitrided if baked below the aging temperature to avoid hydrogen embrittlement — anodizing is not applicable.
Can CB7Cu-2 be formed, bent or molded?
Sand or investment cast with generous risering and chills to avoid shrinkage porosity; HIP is common for aerospace castings, then solution treat ~1040 °C, air/oil quench and single-step age.
What is the maximum service temperature of CB7Cu-2?
CB7Cu-2 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CB7Cu-2-H1100 and CB7Cu-2-H900?
H1100 is the default condition — most commonly stocked casting condition — good compromise of strength, toughness and corrosion resistance. H900: choose for maximum strength and hardness where toughness and SCC resistance are secondary. Yield strength is 860 MPa in H1100 versus 1,210 MPa in H900.
How much does CB7Cu-2 cost?
CB7Cu-2 is a premium-cost stainless steel ($$$), cheaper than about 51% 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 A747/A747M — Steel Castings, Stainless, Precipitation Hardening — ASTM International (2019)
- ASTM A957 — Investment Castings, Steel and Alloy, Common Requirements — ASTM International (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ATI 15-5PH (S15500) Precipitation Hardening Stainless Steel Technical Data — ATI Specialty Materials (2020)
- MMPDS-17 — 15-5PH stainless steel design allowables — Battelle/FAA (2022)
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.