Copper Alloy C37700-M30
Temper · default condition
UNS C37700 · ASTM B124 · EN CW612N, CW602N · JIS C3771
M30 = as hot extruded
Standard condition of finished hot forgings and forging stock — best combination of ductility and machinability.
Values for the M30 condition
Other C37700 tempers and conditions
C37700 is listed in 5 conditions; see the grade overview at C37700.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose when maximum ductility for upsetting, bending or coining is needed after forging. | 115 | 340 | 50 | 85 HB | 28 % IACS |
M30DefaultThis page As hot extruded | Standard condition of finished hot forgings and forging stock — best combination of ductility and machinability. | 140 | 360 | 45 | 100 HB | 27 % IACS |
As hot rolled | Mill condition of extruded forging rod per ASTM B124 before forging or machining. | 145 | 365 | 42 | 105 HB | 27 % IACS |
Quarter hard | Lightly drawn rod for improved straightness, surface finish and chip control in automatic machining. | 275 | 415 | 25 | 120 HB | 26 % IACS |
Half hard | Drawn rod condition when higher yield strength and hardness are required in machined parts. | 310 | 450 | 18 | 135 HB | 26 % IACS |
What is C37700-M30?
C37700-M30 is C37700 in the M30 temper — standard condition of finished hot forgings and forging stock — best combination of ductility and machinability. C37700-M30 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 74% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi). C37700-M30 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 70% of copper alloy grades. It melts at 885°C (1,625 °F).
Advantages
- Low embodied carbon — 3 kg CO₂/kg, better than 97% of copper alloy grades
- Ductile — tolerates forming and impact — 45%, better than 91% of copper alloy grades
- Easy to machine — 80/100, better than 86% of copper alloy grades
Limitations
- Needs corrosion protection — 46/100, worse than 96% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C37700-M30 properties
Typical room-temperature values for C37700-M30; 20 are specific to this condition. Other listed values are C37700 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C37700-M30 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 70% of copper alloy grades. It melts at 885°C (1,625 °F).
Mechanical14
C37700-M30 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 74% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C37700-M30 is rated for continuous service to 200°C (392 °F). It conducts heat at 116 W/m·K (67 BTU/hr·ft·°F), better than 64% of copper alloy grades. Thermal expansion is 20.8 µm/m·K (11.6 µin/in·°F).
Electrical3
C37700-M30 conducts electricity at 27 % IACS, better than 67% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (46/100), worse than 96% of copper alloy grades.
Sustainability4
Producing a kilogram of C37700-M30 takes about 50 MJ of energy and emits 3 kg of CO₂ — less than 89% of copper alloy grades. Typical recycled content is 70%.
Manufacturability7
C37700-M30's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (25/100); formability fair (38/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C37700-M30
Is C37700 easy to machine?
Turns and drills freely with rating ~80 % of C36000; use positive-rake carbide or HSS, high speed, light feeds and flood emulsion; lead-free substitutes needed for potable-water parts.
Can C37700 be welded?
Fusion welding is not recommended (lead embrittlement, zinc fume); join by soldering, silver brazing or mechanical assembly, with proper zinc/lead fume extraction.
Can C37700 be formed, bent or molded?
Excellent hot forgeability at 650–760 °C with low forging pressures; cold forming, heavy bending and coining are limited by the β-phase — anneal first or upset hot.
What surface finishes work on C37700?
Buffs to a bright yellow finish and takes Ni/Cr, tin or lacquer coatings readily; stress-relieve forgings (~260–290 °C) before plating to avoid season cracking, and de-lead/pickle for cosmetic parts.
C37700 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 |
|---|---|---|
| CuASTM B124 C37700 | 58 – 61 | 59.5 |
| Pbfree-machining / anti-galling addition | 1.5 – 2.5 | 2 |
| Fe | ≤ 0.3 | — |
| Znremainder, nominally ~38.5 % | balance | — |
C37700-M30 — frequently asked
What is C37700-M30 used for?
C37700-M30 is typically used for plumbing fittings, valve bodies and hardware forgings. In short: standard hot-forging brass; forge-then-machine alloy; 80 machinability rating.
What is the yield strength of C37700-M30?
C37700-M30 has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 360 MPa (52.2 ksi) — weaker than 74% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C37700-M30 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Turns and drills freely with rating ~80 % of C36000; use positive-rake carbide or HSS, high speed, light feeds and flood emulsion; lead-free substitutes needed for potable-water parts.
Can C37700-M30 be welded?
Not readily — weldability is rated poor (25/100). Fusion welding is not recommended (lead embrittlement, zinc fume); join by soldering, silver brazing or mechanical assembly, with proper zinc/lead fume extraction.
What surface finishes work on C37700-M30?
Buffs to a bright yellow finish and takes Ni/Cr, tin or lacquer coatings readily; stress-relieve forgings (~260–290 °C) before plating to avoid season cracking, and de-lead/pickle for cosmetic parts.
Can C37700-M30 be formed, bent or molded?
Excellent hot forgeability at 650–760 °C with low forging pressures; cold forming, heavy bending and coining are limited by the β-phase — anneal first or upset hot.
What is the maximum service temperature of C37700-M30?
C37700-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 C37700-M30 and C37700-H02?
M30 is the default condition — standard condition of finished hot forgings and forging stock — best combination of ductility and machinability. H02: drawn rod condition when higher yield strength and hardness are required in machined parts. Yield strength is 140 MPa in M30 versus 310 MPa in H02.
Sources
- ASTM B124/B124M — Copper and Copper-Alloy Forging Rod, Bar, and Shapes — ASTM International (2020)
- EN 12165 / EN 12164 — CuZn39Pb2 (CW612N), CuZn36Pb2As (CW602N) — CEN (2016)
- C37700 Forging Brass alloy datasheet — Copper Development Association (copper.org) (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.