Copper Alloy BC3 F-PM
Finish state
GB BC3
Choose for repeat-run small parts needing tighter dimensions and a finer, slightly stronger structure than sand casting.
Values for the F-PM condition
Other BC3 tempers and conditions
BC3 is listed in 4 conditions; see the grade overview at BC3.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
F-SCDefault F | Standard supply condition for valve bodies, pump housings and general pressure castings. | 145 | 290 | 18 | 75 HB | 12 % IACS |
F-PMThis page F | Choose for repeat-run small parts needing tighter dimensions and a finer, slightly stronger structure than sand casting. | 155 | 300 | 16 | 80 HB | 12 % IACS |
F | For large-diameter sleeves, worm-gear rims and pump wear rings requiring pressure tightness over long sections. | 165 | 310 | 15 | 85 HB | 12 % IACS |
F | Best choice for machined bushings, bearings and wear rings — dense, porosity-free bar stock with the highest strength and hardness. | 175 | 320 | 13 | 90 HB | 12 % IACS |
What is BC3 F-PM?
BC3 F-PM is BC3 supplied in the F-PM condition — choose for repeat-run small parts needing tighter dimensions and a finer, slightly stronger structure than sand casting. BC3 F-PM has a yield strength of 155 MPa (22.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 103 GPa (14.9 Msi). BC3 F-PM 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). F-SC is the default condition FabDigit quotes; F-PM is available on request or by drawing note.
Advantages
- Easy to machine — 62/100, better than 75% of copper alloy grades
Limitations
- Limited formability — 12/100, worse than 85% of copper alloy grades
BC3 F-PM properties
Typical room-temperature values for BC3 F-PM; 21 are specific to this condition. Other listed values are BC3 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
BC3 F-PM 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
BC3 F-PM has a yield strength of 155 MPa (22.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 65% of copper alloy grades. Elongation at break is 16% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
BC3 F-PM is rated for continuous service to 250°C (482 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), worse than 69% of copper alloy grades. Thermal expansion is 18.2 µm/m·K (10.1 µin/in·°F).
Electrical3
BC3 F-PM conducts electricity at 12 % IACS, worse than 62% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (71/100), better than 80% of copper alloy grades.
Sustainability4
Producing a kilogram of BC3 F-PM takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 75%.
Manufacturability8
BC3 F-PM's machinability is good (62/100, better than 75% of copper alloy grades); weldability poor (30/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with BC3 F-PM
Is BC3 easy to machine?
Machines freely with sharp positive-rake carbide or HSS tooling at ~40 % of AISI 1212; small Pb content gives short chips, but keep feeds steady to avoid smearing the soft matrix.
Can BC3 be welded?
Fusion welding is poor (hot-short, Sn/Pb segregation); repair by GTAW with phosphor-bronze filler and preheat only on non-pressure areas, and prefer brazing or soldering for joints.
Can BC3 be formed, bent or molded?
Cast-only alloy — good fluidity and pressure tightness in sand, permanent-mould, centrifugal and continuous casting; use directional solidification and chills to control the wide freezing range and interdendritic shrinkage.
What surface finishes work on BC3?
Not anodizable; finish by machining/polishing, chemical patina, tin or nickel plating for potable-water parts, or clear lacquer to retain the bronze colour.
BC3 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 | 9 – 11 | 10 |
| Zn | 1 – 3 | 2 |
| Pbresidual/intentional lead for machinability; C92300 permits 0.30–1.0 | ≤ 1 | 0.5 |
| Ni | ≤ 1 | — |
| Fe | ≤ 0.2 | — |
| Sb | ≤ 0.2 | — |
| Pdeoxidizer residual | ≤ 0.05 | — |
| S | ≤ 0.05 | — |
| Alkept very low to avoid casting defects | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| Cubalance in JIS H5120 CAC403 | ≥ 86.5 (balance) | — |
BC3 F-PM — frequently asked
What is BC3 F-PM used for?
BC3 F-PM is typically used for valve bodies, pump castings and bushings. In short: free-machining gun metal; pressure-tight valve bronze; low-cost bearing casting.
What is the yield strength of BC3 F-PM?
BC3 F-PM has a typical yield strength of 155 MPa (22.5 ksi) and a tensile strength of 300 MPa (43.5 ksi) — weaker than 65% of copper alloy grades. Strength varies by condition: see the 4 listed tempers.
Is BC3 F-PM easy to machine?
Reasonably — machinability is rated good (62/100, better than 75% of copper alloy grades). Machines freely with sharp positive-rake carbide or HSS tooling at ~40 % of AISI 1212; small Pb content gives short chips, but keep feeds steady to avoid smearing the soft matrix.
Can BC3 F-PM be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is poor (hot-short, Sn/Pb segregation); repair by GTAW with phosphor-bronze filler and preheat only on non-pressure areas, and prefer brazing or soldering for joints.
What surface finishes work on BC3 F-PM?
Not anodizable; finish by machining/polishing, chemical patina, tin or nickel plating for potable-water parts, or clear lacquer to retain the bronze colour.
Can BC3 F-PM be formed, bent or molded?
Cast-only alloy — good fluidity and pressure tightness in sand, permanent-mould, centrifugal and continuous casting; use directional solidification and chills to control the wide freezing range and interdendritic shrinkage.
What is the maximum service temperature of BC3 F-PM?
BC3 F-PM 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 BC3 F-SC and BC3 F-CC?
F-SC is the default condition — standard supply condition for valve bodies, pump housings and general pressure castings. F-CC: best choice for machined bushings, bearings and wear rings — dense, porosity-free bar stock with the highest strength and hardness. Yield strength is 145 MPa in F-SC versus 175 MPa in F-CC.
Sources
- JIS H5120 Copper alloy castings (CAC403 / BC3) — JSA (2016)
- ASTM B584 Copper Alloy Sand Castings for General Applications (C92300) — ASTM (2022)
- CDA Alloy Datasheet C92300 (leaded tin bronze) — 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.