Copper Alloy C67500
UNS C67500 · ASTM B138 · EN CW721R
High-strength manganese bronze, classically known as "propeller bronze," prized for its combination of strength, corrosion resistance and castable-weldable behavior in ship propeller and valve applications.
Reference datasheet — C67500 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 H02 condition
C67500 tempers and conditions
C67500 is supplied in 6 conditions, soft to hard. H02 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for maximum ductility when parts must be bent, upset or further cold worked before final machining. | 207 | 448 | 33 | 130 HB | 24 % IACS |
As hot forged and air cooled | Standard condition for hot-forged propeller hubs, blade flanges and valve bodies where uniform mid-range properties are wanted. | 207 | 483 | 30 | 140 HB | 24 % IACS |
As hot extruded | Mill-standard condition for large-diameter rod, hollow bar and profiles supplied straight from the extrusion press. | 240 | 490 | 25 | 145 HB | 24 % IACS |
As forged and quenched | Water-quenched from forging heat to retain more β phase — higher strength and finer structure than air-cooled forgings. | 241 | 517 | 26 | 152 HB | 23 % IACS |
H02Default Half hard | The standard stocked condition for machined shafts, valve stems and fasteners — best balance of strength, straightness and remaining ductility. | 310 | 517 | 20 | 160 HB | 24 % IACS |
Full hard | Pick when maximum strength, wear resistance and thread/bearing hardness are needed and bending is not required. | 414 | 579 | 15 | 180 HB | 23 % IACS |
What is C67500?
High-strength manganese bronze, classically known as "propeller bronze," prized for its combination of strength, corrosion resistance and castable-weldable behavior in ship propeller and valve applications. C67500 has a density of 8.36 g/cm³ (0.302 lb/in³), lighter than 76% of copper alloy grades. It melts at 865°C (1,589 °F). C67500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi).
What is C67500 used for?
- ship propellers
- valve stems
- marine hardware
- gears
C67500 properties
Typical room-temperature values for C67500-H02; bars are the position among copper alloy grades.
Physical3
C67500 has a density of 8.36 g/cm³ (0.302 lb/in³), lighter than 76% of copper alloy grades. It melts at 865°C (1,589 °F).
Mechanical14
C67500 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C67500 is rated for continuous service to 200°C (392 °F). It conducts heat at 100 W/m·K (57.8 BTU/hr·ft·°F), better than 54% of copper alloy grades. Thermal expansion is 21.2 µm/m·K (11.8 µin/in·°F).
Electrical3
C67500 conducts electricity at 24 % IACS, better than 57% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C67500 takes about 50 MJ of energy and emits 3.4 kg of CO₂ — less than 89% of copper alloy grades. Typical recycled content is 55%.
Manufacturability8
C67500's machinability is poor (32/100, worse than 57% of copper alloy grades); weldability good (55/100); formability fair (40/100).
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. C67500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C67500
Is C67500 easy to machine?
Machinability ~30 % of free-cutting brass — use sharp positive-rake carbide, moderate speeds and generous coolant; chips are tough and stringy because of the low lead content.
Can C67500 be welded?
Weldable by GTAW/GMAW with silicon-bronze or manganese-bronze filler; preheat heavy sections, keep heat input low to limit zinc fume and dezincification of the HAZ.
Can C67500 be formed, bent or molded?
Excellent hot workability at 650–760 °C (forge, extrude, hot bend); cold formability is only fair — anneal at ~600 °C before severe cold bends.
C67500 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 |
|---|---|---|
| Cumay include Ag | 57 – 60 | 58.5 |
| Sn | 0.5 – 1.5 | 1 |
| Feforms Fe-rich dispersoids, grain refiner | 0.8 – 2 | 1.2 |
| Mn | 0.05 – 0.5 | 0.25 |
| Al | ≤ 0.25 | 0.15 |
| Pbimpurity limit | ≤ 0.2 | |
| Znbalance, nominally ~38–39 % | balance |
What surface finishes work on C67500?
Not anodizable; takes bright polishing, nickel/chrome plating and tin plating well, and marine parts are usually left bare or coated with anti-fouling/epoxy systems.
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 C67500 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B138
- EN / DIN / Werkstoff-Nr.
- CW721R
- Trade names
- Propeller Bronze
- Similar grades
- HMn58-2
How much does C67500 cost?
C67500 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.
C67500 — frequently asked
What is C67500 used for?
C67500 is typically used for ship propellers, valve stems, marine hardware and gears. In short: classic propeller bronze; high-strength marine bronze; forges well hot.
What is the yield strength of C67500?
C67500 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 517 MPa (75 ksi) — stronger than 64% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C67500 easy to machine?
Not especially — machinability is rated poor (32/100, worse than 57% of copper alloy grades). Machinability ~30 % of free-cutting brass — use sharp positive-rake carbide, moderate speeds and generous coolant; chips are tough and stringy because of the low lead content.
Can C67500 be welded?
Yes — weldability is rated good (55/100). Weldable by GTAW/GMAW with silicon-bronze or manganese-bronze filler; preheat heavy sections, keep heat input low to limit zinc fume and dezincification of the HAZ.
What surface finishes work on C67500?
Not anodizable; takes bright polishing, nickel/chrome plating and tin plating well, and marine parts are usually left bare or coated with anti-fouling/epoxy systems.
Can C67500 be formed, bent or molded?
Excellent hot workability at 650–760 °C (forge, extrude, hot bend); cold formability is only fair — anneal at ~600 °C before severe cold bends.
What is the maximum service temperature of C67500?
C67500 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 C67500-H02 and C67500-H04?
H02 is the default condition — the standard stocked condition for machined shafts, valve stems and fasteners — best balance of strength, straightness and remaining ductility. H04: pick when maximum strength, wear resistance and thread/bearing hardness are needed and bending is not required. Yield strength is 310 MPa in H02 versus 414 MPa in H04.
How much does C67500 cost?
C67500 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 B138/B138M — Manganese Bronze Rod, Bar and Shapes — ASTM International (2019)
- CDA Alloy C67500 property datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- EN 12163 / CW721R (CuZn40Mn1Fe1) wrought copper alloy rod — CEN (2016)
- GB/T 4423 / GB/T 13808 — HMn58-2 — SAC (2020)
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.