Copper Alloy C69700-M30
Temper
UNS C69700
M30 = as hot extruded
Condition of finished hot forgings (valve bodies, stems) with no subsequent cold work.
Values for the M30 condition
Other C69700 tempers and conditions
C69700 is listed in 6 conditions; see the grade overview at C69700.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Pick when maximum ductility for bending, riveting or secondary forming is needed. | 170 | 415 | 38 | 85 HB | — |
M20Default As hot rolled | Standard stocked condition for extruded rod and bar destined for machining or forging. | 240 | 485 | 28 | 120 HB | — |
M30This page As hot extruded | Condition of finished hot forgings (valve bodies, stems) with no subsequent cold work. | 255 | 500 | 25 | 128 HB | 6.5 % IACS |
Quarter hard | Light cold draw for better straightness, surface finish and moderate strength increase on rod. | 380 | 550 | 18 | 150 HB | — |
Half hard | Use where higher yield strength and good chip control on automatic lathes are required. | 450 | 620 | 12 | 170 HB | — |
Full hard | Maximum strength/wear resistance for stems and shafts; ductility and further forming are limited. | 520 | 690 | 8 | 185 HB | — |
What is C69700-M30?
C69700-M30 is C69700 in the M30 temper — condition of finished hot forgings (valve bodies, stems) with no subsequent cold work. C69700-M30 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 105 GPa (15.2 Msi). C69700-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). M20 is the default condition FabDigit quotes; M30 is available on request or by drawing note.
Advantages
- Low embodied carbon — 2.9 kg CO₂/kg, better than 99% of copper alloy grades
- Easy to machine — 72/100, better than 79% of copper alloy grades
Limitations
- Low electrical conductivity — 6.5 % IACS, worse than 91% of copper alloy grades
- Poor heat conductor — 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 89% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C69700-M30 properties
Typical room-temperature values for C69700-M30; 20 are specific to this condition. Other listed values are C69700 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C69700-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).
Mechanical12
C69700-M30 has a yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 105 GPa (15.2 Msi).
Thermal6
C69700-M30 is rated for continuous service to 200°C (392 °F). It conducts heat at 33 W/m·K (19.1 BTU/hr·ft·°F), worse than 89% of copper alloy grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
C69700-M30 conducts electricity at 6.5 % IACS, worse than 91% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of C69700-M30 takes about 45 MJ of energy and emits 2.9 kg of CO₂ — less than 97% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C69700-M30's machinability is very good (72/100, better than 79% of copper alloy grades); weldability poor (25/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C69700-M30
Is C69700 easy to machine?
Machines well for a silicon brass thanks to the lead: use sharp positive-rake carbide, high speed, light feeds and copious coolant; chips are shorter than lead-free silicon brass but longer than C36000.
Can C69700 be welded?
Not recommended for fusion welding — lead promotes hot cracking and porosity; join by soft soldering or silver brazing with low heat input, or use mechanical joints.
Can C69700 be formed, bent or molded?
Excellent hot workability (extrusion/forging around 650–780 °C); cold formability is only moderate, so anneal between heavy bending or heading operations.
What surface finishes work on C69700?
Polishes to a bright golden finish and takes nickel, chrome or tin plating readily; not anodizable, so use lacquer or patina for decorative parts.
C69700 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 | 75 – 80 | 77.5 |
| Sisolid-solution strengthener; improves dezincification resistance | 2.5 – 3.5 | 3 |
| Pbfree-machining addition | 0.5 – 1.5 | 1 |
| Fe | ≤ 0.2 | — |
| Znremainder, nominally ~18–19% | balance | — |
C69700-M30 — frequently asked
What is C69700-M30 used for?
C69700-M30 is typically used for machined plumbing components, valve parts and hardware fittings. In short: free-machining silicon brass; service to 200 °C; machines faster than C69430.
What is the yield strength of C69700-M30?
C69700-M30 has a typical yield strength of 255 MPa (37 ksi) and a tensile strength of 500 MPa (72.5 ksi) — stronger than 55% of copper alloy grades. Strength varies by condition: see the 6 listed tempers.
Is C69700-M30 easy to machine?
Yes — machinability is rated very good (72/100, better than 79% of copper alloy grades). Machines well for a silicon brass thanks to the lead: use sharp positive-rake carbide, high speed, light feeds and copious coolant; chips are shorter than lead-free silicon brass but longer than C36000.
Can C69700-M30 be welded?
Not readily — weldability is rated poor (25/100). Not recommended for fusion welding — lead promotes hot cracking and porosity; join by soft soldering or silver brazing with low heat input, or use mechanical joints.
What surface finishes work on C69700-M30?
Polishes to a bright golden finish and takes nickel, chrome or tin plating readily; not anodizable, so use lacquer or patina for decorative parts.
Can C69700-M30 be formed, bent or molded?
Excellent hot workability (extrusion/forging around 650–780 °C); cold formability is only moderate, so anneal between heavy bending or heading operations.
What is the maximum service temperature of C69700-M30?
C69700-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 C69700-M20 and C69700-H04?
M20 is the default condition — standard stocked condition for extruded rod and bar destined for machining or forging. H04: maximum strength/wear resistance for stems and shafts; ductility and further forming are limited. Yield strength is 240 MPa in M20 versus 520 MPa in H04.
Sources
- C69700 alloy datasheet (leaded silicon brass) — Copper Development Association (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASTM B124 / B283 — Copper and copper-alloy forging rod, bar and shapes; die forgings — ASTM International (2020)
- 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.