Copper Alloy C67300-M30
Temper · default condition
UNS C67300 · ASTM B138
M30 = as hot extruded
Standard stocked condition for rod, bar and shapes; best combination of strength, ductility and machinability.
Values for the M30 condition
Other C67300 tempers and conditions
C67300 is listed in 5 conditions; see the grade overview at C67300.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Use when maximum ductility for bending, staking or secondary forming is needed. | 215 | 490 | 33 | 115 HB | 12 % IACS |
As forged and quenched | Choose for near-net-shape marine hardware and valve bodies produced by hot die forging. | 290 | 570 | 25 | 140 HB | 12 % IACS |
M30DefaultThis page As hot extruded | Standard stocked condition for rod, bar and shapes; best combination of strength, ductility and machinability. | 310 | 600 | 22 | 150 HB | 12 % IACS |
Half hard | Cold-drawn condition for close tolerance shafts, stems and gear blanks needing higher yield strength. | 415 | 640 | 18 | 170 HB | 12 % IACS |
Full hard | Maximum-strength drawn bar for heavily loaded pins, wear parts and fasteners; very limited ductility. | 480 | 700 | 12 | 190 HB | 12 % IACS |
What is C67300-M30?
C67300-M30 is C67300 in the M30 temper — standard stocked condition for rod, bar and shapes; best combination of strength, ductility and machinability. C67300-M30 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 22% and the elastic modulus is 103 GPa (14.9 Msi). C67300-M30 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 85% of copper alloy grades. It melts at 855°C (1,571 °F).
Advantages
- Low embodied carbon — 3.3 kg CO₂/kg, better than 90% of copper alloy grades
- Easy to machine — 75/100, better than 80% of copper alloy grades
Limitations
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
C67300-M30 properties
Typical room-temperature values for C67300-M30; 10 are specific to this condition. Other listed values are C67300 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C67300-M30 has a density of 8.19 g/cm³ (0.296 lb/in³), lighter than 85% of copper alloy grades. It melts at 855°C (1,571 °F).
Mechanical12
C67300-M30 has a yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 64% of copper alloy grades. Elongation at break is 22% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C67300-M30 is rated for continuous service to 200°C (392 °F). It conducts heat at 60 W/m·K (34.7 BTU/hr·ft·°F), worse than 59% of copper alloy grades. Thermal expansion is 20.3 µm/m·K (11.3 µin/in·°F).
Electrical3
C67300-M30 conducts electricity at 12 % IACS, worse than 62% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 68% of copper alloy grades.
Sustainability4
Producing a kilogram of C67300-M30 takes about 52 MJ of energy and emits 3.3 kg of CO₂ — less than 87% of copper alloy grades. Typical recycled content is 45%.
Manufacturability7
C67300-M30's machinability is very good (75/100, better than 80% of copper alloy grades); weldability poor (20/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C67300-M30
Is C67300 easy to machine?
Free-machining behaviour thanks to lead and the β phase — sharp positive-rake carbide or HSS tools, high speeds, light feeds, short chips; expect ~75 % of C36000 rates.
Can C67300 be welded?
Fusion welding not recommended (lead cracking, zinc fume); join by brazing, silver soldering or mechanical fastening, with good ventilation.
Can C67300 be formed, bent or molded?
Excellent hot workability at 650–750 °C (extrusion, hot forging); cold bending is limited — anneal or design for hot-formed shapes.
What surface finishes work on C67300?
Polishes to a bright gold tone; accepts nickel, chrome or tin plating and chemical/black-oxide colouring — no anodising; use clear lacquer to prevent tarnish.
C67300 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 | 58 – 63 | 60.5 |
| Mn | 2 – 3.5 | 2.7 |
| Al | 0.25 – 3 | 1 |
| Si | 0.5 – 1.5 | 0.9 |
| Pbadded for machinability | 0.4 – 3 | 1 |
| Fe | ≤ 0.5 | 0.2 |
| Sn | ≤ 0.3 | — |
| Ni | ≤ 0.25 | — |
| Znremainder, nominally ~32 % | balance | — |
C67300-M30 — frequently asked
What is C67300-M30 used for?
C67300-M30 is typically used for marine propeller hubs, gears, valve stems and heavy-duty fittings. In short: free-machining manganese bronze; 600 MPa tensile bar; hot-forging grade.
What is the yield strength of C67300-M30?
C67300-M30 has a typical yield strength of 310 MPa (45 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 64% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C67300-M30 easy to machine?
Yes — machinability is rated very good (75/100, better than 80% of copper alloy grades). Free-machining behaviour thanks to lead and the β phase — sharp positive-rake carbide or HSS tools, high speeds, light feeds, short chips; expect ~75 % of C36000 rates.
Can C67300-M30 be welded?
Not readily — weldability is rated poor (20/100). Fusion welding not recommended (lead cracking, zinc fume); join by brazing, silver soldering or mechanical fastening, with good ventilation.
What surface finishes work on C67300-M30?
Polishes to a bright gold tone; accepts nickel, chrome or tin plating and chemical/black-oxide colouring — no anodising; use clear lacquer to prevent tarnish.
Can C67300-M30 be formed, bent or molded?
Excellent hot workability at 650–750 °C (extrusion, hot forging); cold bending is limited — anneal or design for hot-formed shapes.
What is the maximum service temperature of C67300-M30?
C67300-M30 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 C67300-M30 and C67300-H04?
M30 is the default condition — standard stocked condition for rod, bar and shapes; best combination of strength, ductility and machinability. H04: maximum-strength drawn bar for heavily loaded pins, wear parts and fasteners; very limited ductility. Yield strength is 310 MPa in M30 versus 480 MPa in H04.
Sources
- ASTM B138 / B138M — Manganese Bronze Rod, Bar and Shapes — ASTM International (2019)
- ASTM B283 — Copper and Copper-Alloy Die Forgings (Hot-Pressed) — ASTM International (2020)
- CDA Standard Designation & Alloy Property Datasheets (UNS C67300) — 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.