Copper Alloy HBsC3-SR (Stress relieved)
Heat-treated state
Use for thick or intricate seawater castings where residual stress plus chlorides/ammonia would risk stress-corrosion cracking; strength drops only slightly.
Values for the SR condition
Other HBsC3 tempers and conditions
HBsC3 is listed in 4 conditions; see the grade overview at HBsC3.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SRThis page Stress relieved | Use for thick or intricate seawater castings where residual stress plus chlorides/ammonia would risk stress-corrosion cracking; strength drops only slightly. | 305 | 645 | 20 | 172 HB | 8.5 % IACS |
F-SANDDefault F | Default stocked/ordered condition: as-cast sand or shell mould castings meeting JIS H5120 CAC303 minimums. | 320 | 660 | 18 | 180 HB | 8 % IACS |
F | Pick for machined bar, nuts and worm-wheel blanks; sound, low-porosity stock with uniform properties along the bar. | 345 | 690 | 18 | 185 HB | 8 % IACS |
F | Pick for rings, bushings and sleeves: finer, denser structure gives slightly higher strength and hardness than sand cast. | 350 | 700 | 17 | 190 HB | 8 % IACS |
What is HBsC3-SR?
HBsC3-SR is HBsC3 heat treated to SR — use for thick or intricate seawater castings where residual stress plus chlorides/ammonia would risk stress-corrosion cracking; strength drops only slightly. HBsC3-SR has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 645 MPa (93.5 ksi) — stronger than 62% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi). HBsC3-SR has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 89% of copper alloy grades. It melts at 890°C (1,634 °F). F-SAND is the default condition FabDigit quotes; SR is available on request or by drawing note.
Limitations
- Hard to polish — 65/100, worse than 87% of copper alloy grades
- Poor heat conductor — 37 W/m·K (21.4 BTU/hr·ft·°F), worse than 85% of copper alloy grades
- Low electrical conductivity — 8.5 % IACS, worse than 79% of copper alloy grades
- Limited formability — 17/100, worse than 75% of copper alloy grades
HBsC3-SR properties
Typical room-temperature values for HBsC3-SR; 20 are specific to this condition. Other listed values are HBsC3 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
HBsC3-SR has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 89% of copper alloy grades. It melts at 890°C (1,634 °F).
Mechanical15
HBsC3-SR has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 645 MPa (93.5 ksi) — stronger than 62% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
HBsC3-SR is rated for continuous service to 200°C (392 °F). It conducts heat at 37 W/m·K (21.4 BTU/hr·ft·°F), worse than 85% of copper alloy grades. Thermal expansion is 19.5 µm/m·K (10.8 µin/in·°F).
Electrical3
HBsC3-SR conducts electricity at 8.5 % IACS, worse than 79% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 64% of copper alloy grades.
Sustainability4
Producing a kilogram of HBsC3-SR takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 55%.
Manufacturability7
HBsC3-SR's machinability is fair (36/100, better than 55% of copper alloy grades); weldability poor (32/100); formability poor (17/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with HBsC3-SR
Is HBsC3 easy to machine?
Machines like a tough bronze rather than free-cutting brass: use sharp positive-rake carbide, moderate speed with generous feed and coolant; hard Fe/Al-rich particles accelerate tool wear.
Can HBsC3 be welded?
Fusion welding and weld repair are difficult (aluminium oxide film, zinc fume, hot cracking) — braze or mechanically join where possible, and stress-relieve any weldment.
Can HBsC3 be formed, bent or molded?
Casting alloy only: pour ~1000–1050 °C with good degassing, chills and generous risers to avoid shrinkage porosity; not suitable for cold forming.
What surface finishes work on HBsC3?
Takes a bright polish and can be chrome- or nickel-plated after careful cleaning of the Al-oxide film; no anodizing — use lacquer or paint for atmospheric protection.
HBsC3 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 |
|---|---|---|
| CuJIS H5120 CAC303 | 60 – 65 | 62.5 |
| Almain strengthener (β-phase former) | 3 – 5 | 4.2 |
| Mn | 2.5 – 5 | 3.5 |
| Fegrain refinement / wear resistance | 0.5 – 2 | 1.2 |
| Pbimpurity limit | ≤ 0.2 | — |
| Snimpurity limit | ≤ 0.2 | — |
| Niimpurity limit | ≤ 0.5 | — |
| Siimpurity limit | ≤ 0.1 | — |
| Znremainder, nominally ~28 % | balance | — |
HBsC3-SR — frequently asked
What is HBsC3-SR used for?
HBsC3-SR is typically used for propeller components, heavy-duty bushings and pump housings. In short: highest-strength cast brass; marine-duty casting alloy; tough, non-free-cutting brass.
What is the yield strength of HBsC3-SR?
HBsC3-SR has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 645 MPa (93.5 ksi) — stronger than 62% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is HBsC3-SR easy to machine?
Not especially — machinability is rated fair (36/100, better than 55% of copper alloy grades). Machines like a tough bronze rather than free-cutting brass: use sharp positive-rake carbide, moderate speed with generous feed and coolant; hard Fe/Al-rich particles accelerate tool wear.
Can HBsC3-SR be welded?
Not readily — weldability is rated poor (32/100). Fusion welding and weld repair are difficult (aluminium oxide film, zinc fume, hot cracking) — braze or mechanically join where possible, and stress-relieve any weldment.
What surface finishes work on HBsC3-SR?
Takes a bright polish and can be chrome- or nickel-plated after careful cleaning of the Al-oxide film; no anodizing — use lacquer or paint for atmospheric protection.
Can HBsC3-SR be formed, bent or molded?
Casting alloy only: pour ~1000–1050 °C with good degassing, chills and generous risers to avoid shrinkage porosity; not suitable for cold forming.
What is the maximum service temperature of HBsC3-SR?
HBsC3-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 HBsC3 F-SAND and HBsC3 F-CENT?
F-SAND is the default condition — default stocked/ordered condition: as-cast sand or shell mould castings meeting JIS H5120 CAC303 minimums. F-CENT: pick for rings, bushings and sleeves: finer, denser structure gives slightly higher strength and hardness than sand cast. Yield strength is 320 MPa in F-SAND versus 350 MPa in F-CENT.
Sources
- JIS H5120 Copper and copper alloy castings (CAC303 / HBsC3) — JSA (2016)
- GB/T 1176 Cast copper and copper alloys (ZCuZn25Al6Fe3Mn3) — SAC (2013)
- ASM Handbook Vol.2 — Properties of Copper and Copper Alloys (cast high-strength brasses) — ASM International (1990)
- CDA alloy datasheets C86200 / C86300 (manganese bronze) — Copper Development Association (2023)
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.