Copper Alloy C87200-SR (Stress relieved)
Heat-treated state
UNS C87200
Use after heavy welding or repair to relieve residual stress in pressure castings; strength essentially unchanged.
Values for the SR condition
Other C87200 tempers and conditions
C87200 is listed in 6 conditions; see the grade overview at C87200.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Use after heavy welding or repair to relieve residual stress in pressure castings; strength essentially unchanged. | 155 | 370 | 28 | 80 HB | 6.5 % IACS |
AS-CAST-SANDDefault ASTM B584 | Standard as-cast sand-mould condition for pump housings, valve bodies and general marine castings. | 165 | 379 | 25 | 85 HB | 6 % IACS |
As-Cast (Investment / Precision Cast) | Investment casting for thin-wall, near-net-shape impellers and fittings with as-cast surface finish. | 165 | 380 | 25 | 85 HB | 6 % IACS |
As-Cast (Centrifugal Cast, M02) | Choose for rings, bushings and sleeve blanks needing dense, inclusion-free walls. | 172 | 400 | 25 | 90 HB | 6 % IACS |
As-Cast (Permanent Mold, M05) | Permanent-mould production runs where dimensional repeatability and a finer chill structure are wanted. | 172 | 400 | 22 | 90 HB | 6 % IACS |
As-Cast (Continuous Cast, M07) | Continuous-cast bar/tube stock — finest structure and highest strength, best for machined-from-solid parts. | 185 | 415 | 22 | 95 HB | 6 % IACS |
What is C87200-SR?
C87200-SR is C87200 heat treated to SR — use after heavy welding or repair to relieve residual stress in pressure castings; strength essentially unchanged. C87200-SR has a yield strength of 155 MPa (22.5 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 28% and the elastic modulus is 103 GPa (14.9 Msi). C87200-SR has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F). AS-CAST-SAND is the default condition FabDigit quotes; SR is available on request or by drawing note.
Advantages
- Readily welded — 90/100, better than 98% of copper alloy grades
- Good corrosion resistance — 75/100, better than 90% of copper alloy grades
Limitations
- Poor heat conductor — 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades
- Low electrical conductivity — 6.5 % IACS, worse than 91% of copper alloy grades
C87200-SR properties
Typical room-temperature values for C87200-SR; 19 are specific to this condition. Other listed values are C87200 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C87200-SR has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F).
Mechanical14
C87200-SR has a yield strength of 155 MPa (22.5 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 28% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C87200-SR is rated for continuous service to 200°C (392 °F). It conducts heat at 29 W/m·K (16.8 BTU/hr·ft·°F), worse than 93% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
C87200-SR conducts electricity at 6.5 % IACS, worse than 91% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (75/100), better than 90% of copper alloy grades.
Sustainability4
Producing a kilogram of C87200-SR takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 70%.
Manufacturability7
C87200-SR's machinability is fair (40/100, better than 57% of copper alloy grades); weldability excellent (90/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C87200-SR
Is C87200 easy to machine?
Gummy, stringy chips — rated ~40 % of free-cutting brass; use sharp positive-rake carbide, high speed, generous feed and soluble-oil coolant to avoid built-up edge.
Can C87200 be welded?
Excellent — GTAW/GMAW with ERCuSi-A filler, argon shield, low interpass temperature (<150 °C); no preheat needed on thin sections and no post-weld heat treatment required for most work.
Can C87200 be formed, bent or molded?
Casting alloy only: needs generous gating and risering because of a wide freezing range; chills and directional solidification prevent interdendritic shrinkage in heavy sections.
What surface finishes work on C87200?
Takes a bright mechanical polish and warm brown/statuary patinas; can be tin, nickel or chrome plated; not anodizable — protect with clear lacquer or wax for architectural exposure.
C87200 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 |
|---|---|---|
| Siprincipal strengthening/deoxidising element | 1 – 5 | 4 |
| Zn | ≤ 5 | 3 |
| Fe | ≤ 2.5 | — |
| Mn | ≤ 1.5 | — |
| Al | ≤ 1.5 | — |
| Sn | ≤ 1 | — |
| Pblow-lead; suitable for potable-water service in most jurisdictions | ≤ 0.5 | — |
| Sb | ≤ 0.25 | — |
| S | ≤ 0.05 | — |
| Cu89.0 % min including silver | ≥ 89 (balance) | — |
C87200-SR — frequently asked
What is C87200-SR used for?
C87200-SR is typically used for valve bodies, pump parts, marine hardware and fittings. In short: weldable cast silicon bronze; lead-free pump alloy; 25 % as-cast elongation.
What is the yield strength of C87200-SR?
C87200-SR has a typical yield strength of 155 MPa (22.5 ksi) and a tensile strength of 370 MPa (53.7 ksi) — weaker than 65% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C87200-SR easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Gummy, stringy chips — rated ~40 % of free-cutting brass; use sharp positive-rake carbide, high speed, generous feed and soluble-oil coolant to avoid built-up edge.
Can C87200-SR be welded?
Yes — weldability is rated excellent (90/100). Excellent — GTAW/GMAW with ERCuSi-A filler, argon shield, low interpass temperature (<150 °C); no preheat needed on thin sections and no post-weld heat treatment required for most work.
What surface finishes work on C87200-SR?
Takes a bright mechanical polish and warm brown/statuary patinas; can be tin, nickel or chrome plated; not anodizable — protect with clear lacquer or wax for architectural exposure.
Can C87200-SR be formed, bent or molded?
Casting alloy only: needs generous gating and risering because of a wide freezing range; chills and directional solidification prevent interdendritic shrinkage in heavy sections.
What is the maximum service temperature of C87200-SR?
C87200-SR 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 C87200 AS-CAST-SAND and C87200-SR?
AS-CAST-SAND is the default condition — standard as-cast sand-mould condition for pump housings, valve bodies and general marine castings. SR: use after heavy welding or repair to relieve residual stress in pressure castings; strength essentially unchanged. Yield strength is 165 MPa in AS-CAST-SAND versus 155 MPa in SR.
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)
- ASTM B271 — Copper-Base Alloy Centrifugal Castings — ASTM International (2020)
- CDA Alloy Database — C87200 Cast Silicon Bronze — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
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.