Copper Alloy C67400
UNS C67400 · ASTM B138
C67400 is a manganese- and aluminum-strengthened high-strength brass (manganese bronze type) covered by ASTM B138, with a duplex structure giving 655 MPa tensile, 331 MPa yield and 20 % elongation at 185 HB (88 HRB).
Reference datasheet — C67400 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 M30 condition
C67400 tempers and conditions
C67400 is supplied in 6 conditions, soft to hard. M30 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 when maximum ductility for bending, upsetting or secondary forming is needed. | 260 | 585 | 30 | 150 HB | — |
As hot rolled | Hot-rolled plate, flats and heavy shapes where section size prevents extrusion or drawing. | 305 | 620 | 24 | 170 HB | 8 % IACS |
M30Default As hot extruded | Standard stock condition for rod, bar and shapes; best balance of strength, ductility and price. | 331 | 655 | 20 | 185 HB | 8 % IACS |
Quarter hard | Light cold draw for improved straightness, surface finish and moderate strength gain. | 380 | 655 | 20 | 175 HB | 8 % IACS |
Half hard | Cold-drawn rod for shafts, stems and wear parts needing higher yield strength and hardness. | 450 | 725 | 15 | 200 HB | — |
Half hard and stress relieved | Pick for precision machined marine/structural parts where residual-stress distortion and SCC risk must be minimised at high strength. | 470 | 745 | 14 | 205 HB | — |
What is C67400?
C67400 is a manganese- and aluminum-strengthened high-strength brass (manganese bronze type) covered by ASTM B138, with a duplex structure giving 655 MPa tensile, 331 MPa yield and 20 % elongation at 185 HB (88 HRB). It is chosen for marine shafting, gears and structural hardware that need wear and seawater corrosion resistance, and is supplied as rod, bar and forgings. Machinability is only 28 (about 25 % of free-cutting brass), electrical conductivity is 8 % IACS, service is limited to about 200 °C, and arc welding is fair at best. Where machining volume matters more than strength, C69300 is the closer option. C67400 has a density of 8.36 g/cm³ (0.302 lb/in³), lighter than 76% of copper alloy grades. It melts at 862°C (1,584 °F). C67400 has a yield strength of 331 MPa (48 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 70% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi).
What is C67400 used for?
- marine shafting
- propeller components
- gears
- structural hardware
Limitations
- Poor heat conductor — 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades
- Low electrical conductivity — 8 % IACS, worse than 81% of copper alloy grades
C67400 properties
Typical room-temperature values for C67400-M30; bars are the position among copper alloy grades.
Physical3
C67400 has a density of 8.36 g/cm³ (0.302 lb/in³), lighter than 76% of copper alloy grades. It melts at 862°C (1,584 °F).
Mechanical13
C67400 has a yield strength of 331 MPa (48 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 70% of copper alloy grades. Elongation at break is 20% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C67400 is rated for continuous service to 200°C (392 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 82% of copper alloy grades. Thermal expansion is 21 µm/m·K (11.7 µin/in·°F).
Electrical3
C67400 conducts electricity at 8 % IACS, worse than 81% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 58% of copper alloy grades.
Sustainability4
Producing a kilogram of C67400 takes about 55 MJ of energy and emits 3.5 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C67400's machinability is poor (28/100, worse than 78% of copper alloy grades); weldability fair (35/100); 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. C67400 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C67400
Is C67400 easy to machine?
Machinable but only ~25 % of free-cutting brass: use rigid setups, sharp carbide, positive rake, moderate speeds and generous coolant; chips are tough and stringy, not free-breaking.
Can C67400 be welded?
Arc welding (GTAW/GMAW with Si-bronze or Al-bronze filler) is only fair — zinc fumes, porosity and HAZ softening; oxyfuel welding is not recommended, soldering is good and brazing fair.
Can C67400 be formed, bent or molded?
Excellent hot workability (extrusion/forging ~650–760 °C); cold formability is limited by the β phase, so keep bends generous and interanneal, then stress-relieve to avoid SCC.
C67400 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 |
|---|---|---|
| Cu | 57 – 60 | 58.5 |
| Mnprimary strengthener | 2 – 3.5 | 2.7 |
| Si | 0.5 – 1.5 | 1 |
| Alraises strength and wear resistance | 0.5 – 2 | 1.2 |
| Fe | ≤ 0.35 | |
| Sn | ≤ 0.3 | |
| Pb | ≤ 0.5 | |
| Znremainder, nominally ~36 % | balance |
What surface finishes work on C67400?
Takes a good mechanical polish and buffs to a bright gold tone; chrome, nickel or tin plating is straightforward — no anodizing; use conversion/lacquer or patination for outdoor colour stability.
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 C67400 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B138
How much does C67400 cost?
C67400 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.
C67400 — frequently asked
What is C67400 used for?
C67400 is typically used for marine shafting, propeller components, gears and structural hardware. In short: high-strength manganese brass; marine shafting grade; low machinability rating 28.
What is the yield strength of C67400?
C67400 has a typical yield strength of 331 MPa (48 ksi) and a tensile strength of 655 MPa (95 ksi) — stronger than 70% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C67400 easy to machine?
Not especially — machinability is rated poor (28/100, worse than 78% of copper alloy grades). Machinable but only ~25 % of free-cutting brass: use rigid setups, sharp carbide, positive rake, moderate speeds and generous coolant; chips are tough and stringy, not free-breaking.
Can C67400 be welded?
With care — weldability is rated fair (35/100). Arc welding (GTAW/GMAW with Si-bronze or Al-bronze filler) is only fair — zinc fumes, porosity and HAZ softening; oxyfuel welding is not recommended, soldering is good and brazing fair.
What surface finishes work on C67400?
Takes a good mechanical polish and buffs to a bright gold tone; chrome, nickel or tin plating is straightforward — no anodizing; use conversion/lacquer or patination for outdoor colour stability.
Can C67400 be formed, bent or molded?
Excellent hot workability (extrusion/forging ~650–760 °C); cold formability is limited by the β phase, so keep bends generous and interanneal, then stress-relieve to avoid SCC.
What is the maximum service temperature of C67400?
C67400 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 C67400-M30 and C67400-HR02?
M30 is the default condition — standard stock condition for rod, bar and shapes; best balance of strength, ductility and price. HR02: pick for precision machined marine/structural parts where residual-stress distortion and SCC risk must be minimised at high strength. Yield strength is 331 MPa in M30 versus 470 MPa in HR02.
How much does C67400 cost?
C67400 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)
- Copper Alloy C67400 alloy data (UNS C67400) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.