Copper Alloy C69430-M30
Temper · default condition
UNS C69430
M30 = as hot extruded
Standard stocked condition for silicon-brass rod and forging stock; balanced strength and ductility.
Values for the M30 condition
Other C69430 tempers and conditions
C69430 is listed in 5 conditions; see the grade overview at C69430.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose for maximum ductility before heavy cold forming, bending or upsetting. | 195 | 450 | 38 | 110 HB | 7 % IACS |
M30DefaultThis page As hot extruded | Standard stocked condition for silicon-brass rod and forging stock; balanced strength and ductility. | 240 | 515 | 30 | 140 HB | — |
Extruded and drawn | Lightly drawn rod with better size tolerance and straightness than as-extruded, still readily machined and formed. | 310 | 585 | 25 | 155 HB | 6.5 % IACS |
Half hard | Pick where higher yield strength and cleaner machined finish are needed, e.g. valve stems and threaded fittings. | 345 | 620 | 22 | 170 HB | 6.6 % IACS |
Full hard | Maximum strength and wear resistance for stems, shafts and fasteners where little further forming is required. | 415 | 690 | 18 | 190 HB | 6.5 % IACS |
What is C69430-M30?
C69430-M30 is C69430 in the M30 temper — standard stocked condition for silicon-brass rod and forging stock; balanced strength and ductility. C69430-M30 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 52% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 103 GPa (14.9 Msi). C69430-M30 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F).
Advantages
- Readily welded — 75/100, better than 89% of copper alloy grades
- Ductile — tolerates forming and impact — 30%, better than 75% of copper alloy grades
Limitations
- Poor heat conductor — 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades
- Low electrical conductivity — 6.7 % IACS, worse than 89% of copper alloy grades
C69430-M30 properties
Typical room-temperature values for C69430-M30; 10 are specific to this condition. Other listed values are C69430 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C69430-M30 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 820°C (1,508 °F).
Mechanical13
C69430-M30 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 52% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C69430-M30 is rated for continuous service to 200°C (392 °F). It conducts heat at 28 W/m·K (16.2 BTU/hr·ft·°F), worse than 96% of copper alloy grades. Thermal expansion is 20.2 µm/m·K (11.2 µin/in·°F).
Electrical3
C69430-M30 conducts electricity at 6.7 % IACS, worse than 89% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), better than 76% of copper alloy grades.
Sustainability4
Producing a kilogram of C69430-M30 takes about 58 MJ of energy and emits 3.8 kg of CO₂ — more than 61% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C69430-M30's machinability is fair (40/100, better than 57% of copper alloy grades); weldability very good (75/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C69430-M30
Is C69430 easy to machine?
Machines like a tough alpha brass, not a leaded one — use sharp positive-rake carbide, high speed, generous coolant and chip breakers; expect ~30–40 % of C36000 productivity.
Can C69430 be welded?
One of the few brasses that welds well: GTAW/GMAW with silicon-bronze (ERCuSi-A) filler, resistance and braze welding all practical with low zinc fuming.
Can C69430 be formed, bent or molded?
Excellent hot workability at 650–800 °C for extrusion and forging; cold bending and heading are only fair, so anneal between heavy operations.
What surface finishes work on C69430?
Polishes to a bright golden finish; accepts nickel, chrome and tin plating and benzotriazole/lacquer protection — no anodizing.
C69430 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 | 80 – 83 | 81.5 |
| Si | 3.5 – 4.5 | 4 |
| Asdezincification inhibitor — distinguishes C69430 from C69400 | 0.03 – 0.06 | 0.05 |
| Pblow-lead / potable-water compliant | ≤ 0.09 | — |
| Fe | ≤ 0.2 | — |
| Znremainder, nominally ~15–16 % | balance | — |
C69430-M30 — frequently asked
What is C69430-M30 used for?
C69430-M30 is typically used for plumbing fittings, weldable brass hardware and decorative fittings. In short: weldable silicon brass; lead-free plumbing alloy; high strength, fair machining.
What is the yield strength of C69430-M30?
C69430-M30 has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 515 MPa (74.7 ksi) — stronger than 52% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C69430-M30 easy to machine?
Not especially — machinability is rated fair (40/100, better than 57% of copper alloy grades). Machines like a tough alpha brass, not a leaded one — use sharp positive-rake carbide, high speed, generous coolant and chip breakers; expect ~30–40 % of C36000 productivity.
Can C69430-M30 be welded?
Yes — weldability is rated very good (75/100). One of the few brasses that welds well: GTAW/GMAW with silicon-bronze (ERCuSi-A) filler, resistance and braze welding all practical with low zinc fuming.
What surface finishes work on C69430-M30?
Polishes to a bright golden finish; accepts nickel, chrome and tin plating and benzotriazole/lacquer protection — no anodizing.
Can C69430-M30 be formed, bent or molded?
Excellent hot workability at 650–800 °C for extrusion and forging; cold bending and heading are only fair, so anneal between heavy operations.
What is the maximum service temperature of C69430-M30?
C69430-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 C69430-M30 and C69430-H04?
M30 is the default condition — standard stocked condition for silicon-brass rod and forging stock; balanced strength and ductility. H04: maximum strength and wear resistance for stems, shafts and fasteners where little further forming is required. Yield strength is 240 MPa in M30 versus 415 MPa in H04.
Sources
- ASTM B371/B371M — Copper-Zinc-Silicon Alloy Rod — ASTM International (2019)
- CDA/UNS Alloy Datasheet C69400 / C69430 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (copper alloys) — ASM International (2005)
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.