Copper Alloy C49300-O61
Heat-treated state
UNS C49300
O61 = annealed
Pick when maximum ductility is needed for bending, staking, flaring or heavy cold heading, or to relieve residual stress before service in water.
Values for the O61 condition
Other C49300 tempers and conditions
C49300 is listed in 5 conditions; see the grade overview at C49300.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
O61This page Annealed | Pick when maximum ductility is needed for bending, staking, flaring or heavy cold heading, or to relieve residual stress before service in water. | 120 | 340 | 45 | 65 HB | 27 % IACS |
As hot extruded | Pick for large-diameter rod, hot-forged valve bodies and parts machined from as-extruded stock where strength demands are modest. | 150 | 370 | 30 | 85 HB | 26 % IACS |
Quarter hard | Compromise temper for parts that must be both cold-formed and machined, e.g. drawn rod for headed water fittings. | 240 | 400 | 25 | 105 HB | 26 % IACS |
H02Default Half hard | Default stocked condition for CNC/screw-machine rod: best balance of strength, straightness, surface finish and chip control. | 310 | 440 | 18 | 125 HB | 26 % IACS |
Full hard | Pick for maximum strength, wear resistance and stiffness of thin sections such as spindles, stems and fasteners; ductility and forming are limited. | 420 | 520 | 8 | 155 HB | 25 % IACS |
What is C49300-O61?
C49300-O61 is C49300 heat treated to O61 — pick when maximum ductility is needed for bending, staking, flaring or heavy cold heading, or to relieve residual stress before service in water. C49300-O61 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 79% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 103 GPa (14.9 Msi). C49300-O61 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 65% of copper alloy grades. It melts at 885°C (1,625 °F). H02 is the default condition FabDigit quotes; O61 is available on request or by drawing note.
Advantages
- Low embodied carbon — 3.1 kg CO₂/kg, better than 95% 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
- Forms and bends easily — 75/100, better than 82% of copper alloy grades
Limitations
- Low strength — 120 MPa (17.4 ksi), worse than 79% of copper alloy grades
C49300-O61 properties
Typical room-temperature values for C49300-O61; 14 are specific to this condition. Other listed values are C49300 reference data and may not represent this condition. Bars are the position among copper alloy grades.
Physical3
C49300-O61 has a density of 8.5 g/cm³ (0.307 lb/in³), lighter than 65% of copper alloy grades. It melts at 885°C (1,625 °F).
Mechanical13
C49300-O61 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 79% of copper alloy grades. Elongation at break is 45% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C49300-O61 is rated for continuous service to 200°C (392 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 58% of copper alloy grades. Thermal expansion is 20.5 µm/m·K (11.4 µin/in·°F).
Electrical3
C49300-O61 conducts electricity at 27 % IACS, better than 67% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 69% of copper alloy grades.
Sustainability4
Producing a kilogram of C49300-O61 takes about 45 MJ of energy and emits 3.1 kg of CO₂ — less than 97% of copper alloy grades. Typical recycled content is 40%.
Manufacturability8
C49300-O61's machinability is very good (80/100, better than 86% of copper alloy grades); weldability poor (30/100); formability very good (75/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C49300-O61
Is C49300 easy to machine?
Runs on screw machines and CNC at C36000-like speeds with 85–90 % of its machinability; use sharp positive-rake carbide or PCD, high-pressure coolant and slightly larger chip loads because Bi chips are stringier than Pb chips.
Can C49300 be welded?
Fusion welding is not recommended (Zn fume, Bi hot-shortness); join by soldering, silver brazing or mechanical/adhesive methods.
Can C49300 be formed, bent or molded?
Hot extrude/forge in a narrow 650–750 °C window — above that bismuth films embrittle grain boundaries; cold heading and bending are best done in O61 or H01 temper with interstage annealing at 450–550 °C.
What surface finishes work on C49300?
Takes bright polishing, Ni/Cr, Sn and PVD coatings well; degrease and mildly pickle first, and stress-relieve (250–300 °C) machined parts to avoid season cracking before plating.
C49300 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 |
|---|---|---|
| Cuper CDA/UNS C49300 registration | 70 – 73 | 71.5 |
| Snimproves dezincification and erosion resistance | 2 – 3 | 2.5 |
| Bifree-cutting chip-breaking phase replacing Pb | 1.5 – 2.5 | 2 |
| Pdezincification inhibitor / deoxidizer | 0.02 – 0.15 | 0.06 |
| Fe | ≤ 0.2 | — |
| Pblead-free limit (NSF 61 / EU 4MS weighted-average compliance) | ≤ 0.09 | — |
| Znbalance, approx. 22–26 % | balance | — |
C49300-O61 — frequently asked
What is C49300-O61 used for?
C49300-O61 is typically used for lead-free plumbing fittings, potable water fittings and food-contact hardware. In short: lead-free free-cutting brass; machinability rating 88; potable-water compliant.
What is the yield strength of C49300-O61?
C49300-O61 has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 79% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C49300-O61 easy to machine?
Yes — machinability is rated very good (80/100, better than 86% of copper alloy grades). Runs on screw machines and CNC at C36000-like speeds with 85–90 % of its machinability; use sharp positive-rake carbide or PCD, high-pressure coolant and slightly larger chip loads because Bi chips are stringier than Pb chips.
Can C49300-O61 be welded?
Not readily — weldability is rated poor (30/100). Fusion welding is not recommended (Zn fume, Bi hot-shortness); join by soldering, silver brazing or mechanical/adhesive methods.
What surface finishes work on C49300-O61?
Takes bright polishing, Ni/Cr, Sn and PVD coatings well; degrease and mildly pickle first, and stress-relieve (250–300 °C) machined parts to avoid season cracking before plating.
Can C49300-O61 be formed, bent or molded?
Hot extrude/forge in a narrow 650–750 °C window — above that bismuth films embrittle grain boundaries; cold heading and bending are best done in O61 or H01 temper with interstage annealing at 450–550 °C.
What is the maximum service temperature of C49300-O61?
C49300-O61 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 C49300-H02 and C49300-O61?
H02 is the default condition — default stocked condition for CNC/screw-machine rod: best balance of strength, straightness, surface finish and chip control. O61: pick when maximum ductility is needed for bending, staking, flaring or heavy cold heading, or to relieve residual stress before service in water. Yield strength is 310 MPa in H02 versus 120 MPa in O61.
Sources
- ASTM B927/B124 — brass rod, bar and forgings (UNS C49300) — ASTM International (2023)
- Standard Designations for Wrought and Cast Copper and Copper Alloys (UNS C49xxx bismuth brasses) — Copper Development Association (2022)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (copper alloys) — ASM International (2005)
- Lead-free bismuth brass rod datasheets (free-cutting alternatives to C36000) — Wieland / Mueller / Ningbo Jintian (2023)
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.