Stainless Steel CB7Cu-1
UNS J92180 · ASTM A747 Grade CB7Cu-1
A cast martensitic precipitation-hardening stainless steel, the cast counterpart to wrought 17-4PH (S17400), offering high strength and moderate corrosion resistance after aging heat treatment; used for pump and valve components requiring both strength and corrosion resistance.
Reference datasheet — CB7Cu-1 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 H1150 condition
CB7Cu-1 tempers and conditions
CB7Cu-1 is supplied in 9 conditions, soft to hard. H1150 is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Double overaged 760 °C + 621 °C | Double-overaged condition ordered for sour (H2S) or low-temperature service where maximum toughness and hardness ≤ 22 HRC are required. | 590 | 790 | 18 | 20 HRC | — |
Solution annealed | Supply/intermediate condition for machining or further fabrication before the customer's own aging cycle; not a final service condition per A747. | 760 | 1,030 | 12 | 33 HRC | — |
H1150Default Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Most widely ordered condition: best toughness, ductility and SCC/sour-service behaviour with still-high 790 MPa class yield — default for pump and valve castings. | 790 | 895 | 14 | 28 HRC | 18 W/m·K |
Aged 593 °C (1100 °F) for 4 h | Tougher, lower-hardness temper for parts needing impact resistance and better resistance to stress-corrosion cracking. | 860 | 950 | 13 | 30 HRC | — |
Aged 579 °C (1075 °F) for 4 h | Mid-range temper giving ~965 MPa tensile with good toughness and improved chloride SCC resistance. | 930 | 1,000 | 12 | 32 HRC | — |
Aged 552 °C (1025 °F) for 4 h | High strength with usable impact toughness; a frequent choice for pump shafts, impellers and valve bodies. | 1,000 | 1,070 | 11 | 34 HRC | — |
Solution treated + aged 538 °C / 4 h | Balanced strength/toughness step between H925 and H1025; used when a specific 1000 MPa-class yield is required. | 1,070 | 1,140 | 10 | 36 HRC | — |
Aged 496 °C (925 °F) for 4 h | Near-peak strength with slightly better ductility and SCC behaviour than H900; common for high-pressure pump internals. | 1,170 | 1,260 | 9 | 40 HRC | — |
Aged 482 °C (900 °F) for 1 h, peak hardness | Maximum strength and hardness; choose for wear-prone valve trim and high-load parts where toughness and SCC resistance are secondary. | 1,240 | 1,350 | 8 | 42 HRC | 18 W/m·K |
What is CB7Cu-1?
A cast martensitic precipitation-hardening stainless steel, the cast counterpart to wrought 17-4PH (S17400), offering high strength and moderate corrosion resistance after aging heat treatment; used for pump and valve components requiring both strength and corrosion resistance. CB7Cu-1 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,404°C (2,559 °F). CB7Cu-1 has a yield strength of 790 MPa (115 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 196 GPa (28.4 Msi).
What is CB7Cu-1 used for?
- pump casings and impellers
- valve bodies
- marine hardware
- aerospace structural castings
- chemical processing equipment
Advantages
- High strength — 790 MPa (115 ksi), better than 96% of stainless steel grades
- Easy to machine — 45/100, better than 84% of stainless steel grades
Limitations
- Limited formability — 8/100, worse than 97% of stainless steel grades
- Limited ductility — 14%, worse than 91% of stainless steel grades
- Limited service temperature — 315°C (599 °F), worse than 85% of stainless steel grades
CB7Cu-1 properties
Typical room-temperature values for CB7Cu-1-H1150; bars are the position among stainless steel grades.
Physical3
CB7Cu-1 has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,404°C (2,559 °F).
Mechanical16
CB7Cu-1 has a yield strength of 790 MPa (115 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 96% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 196 GPa (28.4 Msi).
Thermal6
CB7Cu-1 is rated for continuous service to 315°C (599 °F). It conducts heat at 18.3 W/m·K (10.6 BTU/hr·ft·°F), better than 73% of stainless steel grades. Thermal expansion is 10.9 µm/m·K (6.06 µin/in·°F).
Electrical3
CB7Cu-1 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of CB7Cu-1 takes about 58 MJ of energy and emits 5 kg of CO₂ — more than 66% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
CB7Cu-1's machinability is fair (45/100, better than 84% of stainless steel grades); weldability good (60/100); formability not recommended (8/100).
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-1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CB7Cu-1
Is CB7Cu-1 easy to machine?
Machine in Condition A or H1150 with rigid setups, sharp positive-rake carbide, 60–110 m/min and heavy feeds to break the work-hardening skin; H900 parts should be finish-ground rather than turned.
Can CB7Cu-1 be welded?
Weldable by GTAW/GMAW with matching 17-4PH (AWS A5.9 ER630) filler, low heat input and no preheat needed on thin sections; re-solution treat and re-age after welding for full properties, or at minimum re-age at the specified H-temperature.
Can CB7Cu-1 be formed, bent or molded?
Cast only — good fluidity in sand and investment moulds, but design generous risers and 3–5 % solidification feed since the alloy is prone to shrinkage porosity in heavy sections; HIP is common for critical parts.
CB7Cu-1 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 | 0.8 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.03 | 0.02 |
| Cr | 15.5 – 17.7 | 16.5 |
| Ni | 3.6 – 4.6 | 4.1 |
| Cuprecipitation-hardening element | 2.5 – 3.2 | 2.9 |
| NbCb; stabilizer | 0.15 – 0.35 | 0.25 |
| Moresidual | ≤ 0.5 | 0.2 |
| Fe | balance |
What surface finishes work on CB7Cu-1?
Passivate per ASTM A967 (nitric or citric) after machining; takes a good mechanical or electropolish; hard chrome, nitriding or PVD can be applied below the aging temperature to avoid over-tempering.
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-1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J92180
- ASTM
- A747 Grade CB7Cu-1
- Also called
- Cast 17-4PH
- Similar grades
- S17400
How much does CB7Cu-1 cost?
CB7Cu-1 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-1 — frequently asked
What is CB7Cu-1 used for?
CB7Cu-1 is typically used for pump casings and impellers, valve bodies, marine hardware, aerospace structural castings and chemical processing equipment. In short: cast 17-4PH equivalent; high-strength PH casting; nine aging conditions.
What is the yield strength of CB7Cu-1?
CB7Cu-1 has a typical yield strength of 790 MPa (115 ksi) and a tensile strength of 895 MPa (130 ksi) — stronger than 96% of stainless steel grades. Strength varies by condition: see the 9 listed tempers.
Is CB7Cu-1 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 84% of stainless steel grades). Machine in Condition A or H1150 with rigid setups, sharp positive-rake carbide, 60–110 m/min and heavy feeds to break the work-hardening skin; H900 parts should be finish-ground rather than turned.
Can CB7Cu-1 be welded?
Yes — weldability is rated good (60/100). Weldable by GTAW/GMAW with matching 17-4PH (AWS A5.9 ER630) filler, low heat input and no preheat needed on thin sections; re-solution treat and re-age after welding for full properties, or at minimum re-age at the specified H-temperature.
What surface finishes work on CB7Cu-1?
Passivate per ASTM A967 (nitric or citric) after machining; takes a good mechanical or electropolish; hard chrome, nitriding or PVD can be applied below the aging temperature to avoid over-tempering.
Can CB7Cu-1 be formed, bent or molded?
Cast only — good fluidity in sand and investment moulds, but design generous risers and 3–5 % solidification feed since the alloy is prone to shrinkage porosity in heavy sections; HIP is common for critical parts.
What is the maximum service temperature of CB7Cu-1?
CB7Cu-1 is rated for continuous use to about 315°C (599 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CB7Cu-1-H1150 and CB7Cu-1-H900?
H1150 is the default condition — most widely ordered condition: best toughness, ductility and SCC/sour-service behaviour with still-high 790 MPa class yield — default for pump and valve castings. H900: maximum strength and hardness; choose for wear-prone valve trim and high-load parts where toughness and SCC resistance are secondary. Yield strength is 790 MPa in H1150 versus 1,240 MPa in H900.
How much does CB7Cu-1 cost?
CB7Cu-1 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 A564/A564M — Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars (17-4PH reference) — 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)
- 17-4 PH Stainless Steel Product Data Bulletin — AK Steel / Cleveland-Cliffs (2016)
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.