Copper Alloy C87700
UNS C87700
C87700 is a high-strength cast silicon bronze in the UNS C87000 series, lead-free and silicon-bearing, produced by sand, permanent-mould, investment and continuous casting.
Reference datasheet — C87700 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 M01 condition
C87700 tempers and conditions
C87700 is supplied in 5 conditions, soft to hard. M01 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M01Default As sand cast | Pick the as-sand-cast delivery state for general-purpose valve bodies, pump housings and plumbing fittings in small to medium volumes, at 415 MPa tensile and 100 HB. | 190 | 415 | 25 | 100 HB | 6.7 % IACS |
As investment cast | Pick for complex thin-wall precision parts: near-net shape and low surface roughness cut machining, at a lower 425 MPa tensile but 24% elongation. | 195 | 425 | 24 | 102 HB | 6.7 % IACS |
As centrifugally cast | Choose as-centrifugally-cast sleeves, flanges and bearing bushes when a denser structure is needed; strength and hardness edge above sand cast at 430 MPa and 105 HB. | 200 | 430 | 24 | 105 HB | 6.7 % IACS |
As plaster cast | Choose for medium-volume thin-wall fittings where faster mold cooling gives finer grain, 450 MPa tensile and better surface quality than sand casting. | 205 | 450 | 22 | 110 HB | 6.8 % IACS |
As continuous cast | Use continuously cast bar and tube stock for machined parts — densest structure with no shrinkage porosity and the highest properties, 460 MPa tensile and 115 HB. | 215 | 460 | 20 | 115 HB | 7 % IACS |
What is C87700?
C87700 is a high-strength cast silicon bronze in the UNS C87000 series, lead-free and silicon-bearing, produced by sand, permanent-mould, investment and continuous casting. Default properties are 190 MPa yield, 415 MPa tensile, 25 % elongation and 100 HB, so it offers more strength than standard Cu–Si casting grades while keeping their corrosion resistance and weldability. Excellent fluidity and a narrow freezing range suit thin-wall, complex shapes. Machinability is about 40–45 % of free-cutting brass and heavy sections need reinforced feeding; C87600 is the closest alternative where an ASTM B584 listing is required. C87700 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F). C87700 has a yield strength of 190 MPa (27.6 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
What is C87700 used for?
- Valve components
- Marine hardware
- Pump parts
- Structural fittings
Advantages
- Readily welded — 80/100, better than 93% of copper alloy grades
- Good corrosion resistance — 72/100, better than 84% of copper alloy grades
Limitations
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades
- Low electrical conductivity — 6.7 % IACS, worse than 89% of copper alloy grades
C87700 properties
Typical room-temperature values for C87700-M01; bars are the position among copper alloy grades.
Physical3
C87700 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F).
Mechanical15
C87700 has a yield strength of 190 MPa (27.6 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C87700 is rated for continuous service to 200°C (392 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C87700 conducts electricity at 6.7 % IACS, worse than 89% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 84% of copper alloy grades.
Sustainability4
Producing a kilogram of C87700 takes about 50 MJ of energy and emits 3.4 kg of CO₂ — less than 89% of copper alloy grades. Typical recycled content is 75%.
Manufacturability8
C87700's machinability is fair (45/100, better than 64% of copper alloy grades); weldability very good (80/100); formability poor (30/100).
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 copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C87700 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C87700
Is C87700 easy to machine?
Lead-free and silicon-bearing, so chips are tough. Use sharp positive-rake carbide at medium-to-high speed with light feed and ample coolant; expect roughly 40–45 % of free-cutting brass rates.
Can C87700 be welded?
Good weldability by GTAW/GMAW with silicon bronze filler (ERCuSi-A). Remove the surface silicon oxide film first and keep interpass temperature low to prevent hot cracking.
Can C87700 be formed, bent or molded?
Excellent fluidity with a narrow freezing range suits thin-wall, complex sand, permanent-mould and investment castings. Heavy sections need enlarged risers to feed shrinkage and avoid porosity.
C87700 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 |
|---|---|---|
| Cumain element of zinc-bearing silicon bronze (silicon brass) | 79 – 85 | 82 |
| Sistrengthens, resists dezincification | 2.5 – 3.5 | 3 |
| Pblead-free grade limit (drinking water use) | ≤ 0.09 | 0.05 |
| Fe | ≤ 0.3 | 0.15 |
| Alexcess promotes dross inclusions | ≤ 0.15 | 0.05 |
| Sn | ≤ 0.3 | 0.1 |
| Ni | ≤ 0.2 | 0.05 |
| Mn | ≤ 0.1 | 0.03 |
| Zn | balance |
What surface finishes work on C87700?
Polishes to a high lustre and accepts chemical colouring or nickel/chrome plating. Not anodizable — bare outdoor exposure forms a brown oxide film, which can be sealed with clear lacquer.
Surface treatments FabDigit runs on copper 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).
How much does C87700 cost?
C87700 is a high-cost copper 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.
C87700 — frequently asked
What is C87700 used for?
C87700 is typically used for valve components, marine hardware, pump parts and structural fittings. In short: high-strength silicon bronze; narrow freezing range; lead-free complex castings.
What is the yield strength of C87700?
C87700 has a typical yield strength of 190 MPa (27.6 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 57% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C87700 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Lead-free and silicon-bearing, so chips are tough. Use sharp positive-rake carbide at medium-to-high speed with light feed and ample coolant; expect roughly 40–45 % of free-cutting brass rates.
Can C87700 be welded?
Yes — weldability is rated very good (80/100). Good weldability by GTAW/GMAW with silicon bronze filler (ERCuSi-A). Remove the surface silicon oxide film first and keep interpass temperature low to prevent hot cracking.
What surface finishes work on C87700?
Polishes to a high lustre and accepts chemical colouring or nickel/chrome plating. Not anodizable — bare outdoor exposure forms a brown oxide film, which can be sealed with clear lacquer.
Can C87700 be formed, bent or molded?
Excellent fluidity with a narrow freezing range suits thin-wall, complex sand, permanent-mould and investment castings. Heavy sections need enlarged risers to feed shrinkage and avoid porosity.
What is the maximum service temperature of C87700?
C87700 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C87700-M01 and C87700-M07?
M01 is the default condition — pick the as-sand-cast delivery state for general-purpose valve bodies, pump housings and plumbing fittings in small to medium volumes, at 415 MPa tensile and 100 HB. M07: use continuously cast bar and tube stock for machined parts — densest structure with no shrinkage porosity and the highest properties, 460 MPa tensile and 115 HB. Yield strength is 190 MPa in M01 versus 215 MPa in M07.
How much does C87700 cost?
C87700 is a high-cost copper 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 B584 — Standard Specification for Copper Alloy Sand Castings for General Applications — ASTM International (2022)
- ASTM B505/B505M — Copper Alloy Continuous Castings — ASTM International (2018)
- CDA/UNS Copper Alloy Properties Database (C87xxx silicon bronze/brass castings) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.