Copper Alloy C69300
UNS C69300
C69300 is a lead-free, silicon-bearing free-machining brass developed as a substitute for leaded brass in plumbing and fittings.
Reference datasheet — C69300 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
C69300 tempers and conditions
C69300 is supplied in 7 conditions, soft to hard. M30 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Pick when maximum ductility for bending, flaring or upsetting of rod/tube is needed. | 210 | 480 | 35 | 120 HB | 6.5 % IACS |
As hot rolled | Use for hot-forged bodies and hot-rolled sections where forged-in properties are acceptable without further drawing. | 270 | 530 | 25 | 140 HB | 6 % IACS |
M30Default As hot extruded | Standard stock condition for lead-free brass bar and hollow rod destined for CNC-machined valves and fittings. | 290 | 550 | 25 | 145 HB | 6 % IACS |
Quarter hard | Light draw for tighter tolerance and straightness with retained ductility for mild forming. | 400 | 590 | 18 | 160 HB | 6 % IACS |
Half hard | Standard cold-drawn condition for high-strength machined parts, fasteners and stems needing good chip control and dimensional accuracy. | 480 | 650 | 13 | 180 HB | 6 % IACS |
Hard drawn | Cold-drawn hollow/tube condition for lead-free water tube and machined bushings from hollow stock. | 520 | 680 | 10 | 190 HB | 5.8 % IACS |
Full hard | Highest-strength drawn rod/wire for shafts, spindles and highly loaded lead-free fittings; little remaining ductility. | 590 | 720 | 8 | 14 HRC | 5.8 % IACS |
What is C69300?
C69300 is a lead-free, silicon-bearing free-machining brass developed as a substitute for leaded brass in plumbing and fittings. It machines at roughly 80 % of C36000 rates with short chips while providing 550 MPa tensile, 290 MPa yield, 25 % elongation and 145 HB (78 HRB), and it hot extrudes and forges well at 700–800 °C in rod, bar and forging forms. Electrical conductivity is 6 % IACS, service is limited to about 200 °C, and cold formability is restricted by the duplex structure (rating 45) while the abrasive silicide phase drives tool wear. Where lead is permitted, C36000 remains the cheaper machining choice. C69300 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F). C69300 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 60% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
What is C69300 used for?
- lead-free plumbing fittings
- valve components
- potable water hardware
Advantages
- Easy to machine — 80/100, better than 86% of copper alloy grades
Limitations
- Low electrical conductivity — 6 % IACS, worse than 93% of copper alloy grades
- Poor heat conductor — 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 90% of copper alloy grades
C69300 properties
Typical room-temperature values for C69300-M30; bars are the position among copper alloy grades.
Physical3
C69300 has a density of 8.3 g/cm³ (0.3 lb/in³), lighter than 80% of copper alloy grades. It melts at 821°C (1,510 °F).
Mechanical13
C69300 has a yield strength of 290 MPa (42.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 60% of copper alloy grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C69300 is rated for continuous service to 200°C (392 °F). It conducts heat at 32 W/m·K (18.5 BTU/hr·ft·°F), worse than 90% of copper alloy grades. Thermal expansion is 18.5 µm/m·K (10.3 µin/in·°F).
Electrical3
C69300 conducts electricity at 6 % IACS, worse than 93% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C69300 takes about 62 MJ of energy and emits 3.8 kg of CO₂ — more than 76% of copper alloy grades. Typical recycled content is 40%.
Manufacturability7
C69300's machinability is very good (80/100, better than 86% of copper alloy grades); weldability fair (45/100); formability fair (45/100).
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. C69300 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C69300
Is C69300 easy to machine?
Machines at roughly 80 % of C36000 rates with short chips; use sharp carbide or PVD-coated tools, positive rake and generous coolant — the silicide phase is abrasive and edge wear, not chip control, sets tool life.
Can C69300 be welded?
TIG/MIG weldable with silicon-bronze filler and good local exhaust for zinc fume; keep heat input low, prefer brazing or soldering for potable-water joints.
Can C69300 be formed, bent or molded?
Excellent hot extrudability and hot forgeability (700–800 °C); cold bending and heading are limited by the duplex structure — anneal (450–550 °C) before severe cold work.
C69300 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 | 73 – 77 | 75 |
| Siforms hard silicide phase for chip breaking | 2.7 – 3.4 | 3 |
| Pdezincification inhibitor | 0.04 – 0.15 | 0.08 |
| Pbimpurity limit — lead-free grade | ≤ 0.09 | |
| Feimpurity limit | ≤ 0.09 | |
| Znremainder, nominally ~21 % | balance |
What surface finishes work on C69300?
Not anodizable; takes fine mechanical/chemical polish, and accepts Ni, Cr and Sn plating after alkaline degrease plus an activation step to strip silicon oxide.
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).
How much does C69300 cost?
C69300 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.
C69300 — frequently asked
What is C69300 used for?
C69300 is typically used for lead-free plumbing fittings, valve components and potable water hardware. In short: lead-free free-machining brass; 80 % of C36000 rates; potable-water plumbing grade.
What is the yield strength of C69300?
C69300 has a typical yield strength of 290 MPa (42.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 60% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C69300 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Machines at roughly 80 % of C36000 rates with short chips; use sharp carbide or PVD-coated tools, positive rake and generous coolant — the silicide phase is abrasive and edge wear, not chip control, sets tool life.
Can C69300 be welded?
With care — weldability is rated fair (45/100). TIG/MIG weldable with silicon-bronze filler and good local exhaust for zinc fume; keep heat input low, prefer brazing or soldering for potable-water joints.
What surface finishes work on C69300?
Not anodizable; takes fine mechanical/chemical polish, and accepts Ni, Cr and Sn plating after alkaline degrease plus an activation step to strip silicon oxide.
Can C69300 be formed, bent or molded?
Excellent hot extrudability and hot forgeability (700–800 °C); cold bending and heading are limited by the duplex structure — anneal (450–550 °C) before severe cold work.
What is the maximum service temperature of C69300?
C69300 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 C69300-M30 and C69300-H04?
M30 is the default condition — standard stock condition for lead-free brass bar and hollow rod destined for CNC-machined valves and fittings. H04: highest-strength drawn rod/wire for shafts, spindles and highly loaded lead-free fittings; little remaining ductility. Yield strength is 290 MPa in M30 versus 590 MPa in H04.
How much does C69300 cost?
C69300 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 B371/B371M — Copper-Zinc-Silicon Alloy Rod — ASTM International (2019)
- CDA/UNS C69300 alloy datasheet — Copper Development Association (2023)
- EcoBrass / CuZn21Si3P rod and forging stock datasheet — Wieland / Diehl Metall (Mitsubishi Shindoh licence) (2022)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- EN 12164 / EN 12165 — Copper and copper alloys, rod and forging stock — CEN (2016)
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.