Copper Alloy BC2
GB BC2
BC2 (C90500) is a JIS gun-metal type tin bronze casting alloy, a copper–tin–zinc composition without a lead addition, standardised for pressure-tight fittings and general machine parts.
Reference datasheet — BC2 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 F-SAND condition
BC2 tempers and conditions
BC2 is supplied in 5 conditions, soft to hard. F-SAND 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 |
|---|---|---|---|---|---|---|
F + stress relieved | Optional low-temperature anneal to stabilise dimensions of thin-walled or heavily machined castings. | 140 | 300 | 22 | 72 HB | 11.5 % IACS |
F-SANDDefault F | Standard supply condition for valve bodies, pump housings and general pressure-tight castings. | 150 | 310 | 20 | 75 HB | 11 % IACS |
F | For large sleeves, worm-gear rims and rings where a dense, inclusion-swept wall is required. | 160 | 320 | 18 | 78 HB | 11 % IACS |
F | Chill-cast finer structure for smaller repeat parts needing better surface and slightly higher strength. | 165 | 340 | 16 | 80 HB | 11 % IACS |
F | Choose for machined bushings, wear rings and bar stock: dense, low-porosity, highest yield strength. | 195 | 330 | 12 | 85 HB | 11 % IACS |
What is BC2?
BC2 (C90500) is a JIS gun-metal type tin bronze casting alloy, a copper–tin–zinc composition without a lead addition, standardised for pressure-tight fittings and general machine parts. Typical properties are 150 MPa yield, 310 MPa tensile, 20 % elongation, 75 HB, 11 % IACS electrical conductivity and service to 250 °C, in sand, permanent-mould, continuous, centrifugal and stress-relieved conditions. It is a casting-only alloy with poor fusion weldability. Choose BC3 (C92300) when free machining matters more, or PBC2 (C90700) for higher-load gears. BC2 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F). BC2 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi).
What is BC2 used for?
- pipe fittings
- pump housings
- small gears
Limitations
- Limited formability — 10/100, worse than 89% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
BC2 properties
Typical room-temperature values for BC2-F-SAND; bars are the position among copper alloy grades.
Physical3
BC2 has a density of 8.8 g/cm³ (0.318 lb/in³), heavier than 58% of copper alloy grades. It melts at 854°C (1,569 °F).
Mechanical15
BC2 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 69% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
BC2 is rated for continuous service to 250°C (482 °F). It conducts heat at 72 W/m·K (41.6 BTU/hr·ft·°F), worse than 52% of copper alloy grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
BC2 conducts electricity at 11 % IACS, worse than 68% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of BC2 takes about 55 MJ of energy and emits 3.4 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 45%.
Manufacturability8
BC2's machinability is fair (45/100, better than 64% of copper alloy grades); weldability poor (25/100); formability not recommended (10/100).
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. BC2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with BC2
Is BC2 easy to machine?
Machines to a short chip at roughly 30% of free-cutting brass; use sharp positive-rake carbide, moderate feeds and generous coolant, and expect slight smearing from the soft alpha matrix.
Can BC2 be welded?
Fusion welding is poor (hot-short, tin oxide films); repair by braze welding or GTAW with matching Cu-Sn filler and preheat 150–250 °C, otherwise prefer brazing/soldering.
Can BC2 be formed, bent or molded?
Casting alloy only — excellent for pressure-tight sand, chill, centrifugal and continuous casting; provide directional solidification and adequate feeding to avoid tin inverse segregation and microporosity.
BC2 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 |
|---|---|---|
| Sn | 7 – 9 | 8 |
| Zn | 3 – 5 | 4 |
| Pbimpurity limit | ≤ 1 | 0.3 |
| Niimpurity limit | ≤ 1 | |
| Feimpurity limit | ≤ 0.2 | |
| Sbimpurity limit | ≤ 0.2 | |
| Pimpurity limit | ≤ 0.05 | |
| Alimpurity limit | ≤ 0.01 | |
| Siimpurity limit | ≤ 0.01 | |
| Mnimpurity limit | ≤ 0.2 | |
| Simpurity limit | ≤ 0.05 | |
| Cu | ≥ 86 (balance) |
What surface finishes work on BC2?
Not anodizable; take a good mechanical polish and accepts tin, nickel or chrome plating, chemical brown/black patination, or clear lacquer for architectural parts.
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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy BC2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- C90500
How much does BC2 cost?
BC2 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.
BC2 — frequently asked
What is BC2 used for?
BC2 is typically used for pipe fittings, pump housings and small gears. In short: lead-free gun metal; pressure-tight general bronze; higher ductility than PBC2.
What is the yield strength of BC2?
BC2 has a typical yield strength of 150 MPa (21.8 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 69% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is BC2 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of copper alloy grades). Machines to a short chip at roughly 30% of free-cutting brass; use sharp positive-rake carbide, moderate feeds and generous coolant, and expect slight smearing from the soft alpha matrix.
Can BC2 be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is poor (hot-short, tin oxide films); repair by braze welding or GTAW with matching Cu-Sn filler and preheat 150–250 °C, otherwise prefer brazing/soldering.
What surface finishes work on BC2?
Not anodizable; take a good mechanical polish and accepts tin, nickel or chrome plating, chemical brown/black patination, or clear lacquer for architectural parts.
Can BC2 be formed, bent or molded?
Casting alloy only — excellent for pressure-tight sand, chill, centrifugal and continuous casting; provide directional solidification and adequate feeding to avoid tin inverse segregation and microporosity.
What is the maximum service temperature of BC2?
BC2 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between BC2 F-SAND and BC2 F-CC?
F-SAND is the default condition — standard supply condition for valve bodies, pump housings and general pressure-tight castings. F-CC: choose for machined bushings, wear rings and bar stock: dense, low-porosity, highest yield strength. Yield strength is 150 MPa in F-SAND versus 195 MPa in F-CC.
How much does BC2 cost?
BC2 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
- JIS H5120 Copper alloy castings (CAC402 / former BC2) — JSA (2016)
- ASTM B584 Standard Specification for Copper Alloy Sand Castings for General Applications (C90300/C90500) — ASTM (2014)
- Copper Alloy Datasheets C90300 / C90500 — 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; 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.