Copper Alloy C33000 · temper · default condition
Copper Alloy C33000-O
Properties of the O condition, compared with the other C33000 tempers.
Softest condition — pick for tight-radius bending, expanding, flaring and forming of tube.
What is C33000-O?
C33000-O is C33000 in the O temper — softest condition — pick for tight-radius bending, expanding, flaring and forming of tube. C33000-O has a yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 81% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 103 GPa (14.9 Msi). C33000-O has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 899°C (1,650 °F).
Advantages
- Ductile — tolerates forming and impact — 55%, better than 98% of copper alloy grades
- Forms and bends easily — 85/100, better than 83% of copper alloy grades
- Easy to machine — 70/100, better than 78% of copper alloy grades
Limitations
- Low strength — 110 MPa (16 ksi), worse than 81% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C33000-O properties
Typical room-temperature values for C33000-O — 9 properties are specific to this condition; the rest are grade-level values shared by every C33000 temper. Each bar shows where the value sits among the copper alloy grades in FabDigit's library — further right is higher.
Physical3
C33000-O has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 899°C (1,650 °F).
Mechanical10
C33000-O has a yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 81% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C33000-O is rated for continuous service to 200°C (392 °F). It conducts heat at 121 W/m·K (69.9 BTU/hr·ft·°F), better than 67% of copper alloy grades. Thermal expansion is 20.2 µm/m·K (11.2 µin/in·°F).
Electrical3
C33000-O conducts electricity at 26 % IACS, better than 62% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C33000-O takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 50%.
Manufacturability7
C33000-O's machinability is very good (70/100, better than 78% of copper alloy grades); weldability poor (25/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other C33000 tempers and conditions
C33000 is also supplied in 6 other conditions. The full side-by-side table is on the C33000 overview.
- ODefaultSoftest condition — pick for tight-radius bending, expanding, flaring and forming of tube.110 MPa yield · 55 HB
- H04Full-hard drawn condition for maximum strength, straightness and best turning finish; little cold forming left.390 MPa yield · 145 HB
- H02Half-hard drawn tube/rod — good compromise of strength, screw-machine performance and moderate forming.275 MPa yield · 110 HB
Working with C33000-O
Is C33000 easy to machine?
Free-cutting-like behaviour at ~80–90% of C36000: use positive-rake carbide or HSS, high speed, light feeds, water-soluble coolant; chips break well thanks to the 0.5% Pb.
Can C33000 be welded?
Not suited to fusion welding (lead cracking and Zn fume); join by soft soldering or silver brazing with flux and controlled heat.
Can C33000 be formed, bent or molded?
Annealed/O50 tube bends, expands, flares and knurls readily; interanneal ~425–600 °C between heavy draws and stress-relieve cold-worked parts (~250–300 °C) to avoid ammonia-induced SCC.
What surface finishes work on C33000?
Polishes to a bright yellow finish; accepts nickel/chrome plating, chemical blackening/antiquing and clear lacquer — no anodizing.
C33000 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 | 65 – 68 | 66 |
| Pbfree-machining addition | 0.25 – 0.7 | 0.5 |
| Fe | ≤ 0.07 | — |
| Znremainder, nominally ~33.5% | balance | — |
C33000-O — frequently asked
What is C33000-O used for?
C33000-O is typically used for heat exchanger and condenser tubes, gas and liquid transfer tubing, machined tube fittings, lighting fixture tubing, hardware and decorative tube and instrument and gauge lines. In short: ductile heat-exchanger brass.
What is the yield strength of C33000-O?
C33000-O has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 81% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C33000-O easy to machine?
Yes — machinability is rated very good (70/100, better than 78% of copper alloy grades). Free-cutting-like behaviour at ~80–90% of C36000: use positive-rake carbide or HSS, high speed, light feeds, water-soluble coolant; chips break well thanks to the 0.5% Pb.
Can C33000-O be welded?
Not readily — weldability is rated poor (25/100). Not suited to fusion welding (lead cracking and Zn fume); join by soft soldering or silver brazing with flux and controlled heat.
What surface finishes work on C33000-O?
Polishes to a bright yellow finish; accepts nickel/chrome plating, chemical blackening/antiquing and clear lacquer — no anodizing.
Can C33000-O be formed, bent or molded?
Annealed/O50 tube bends, expands, flares and knurls readily; interanneal ~425–600 °C between heavy draws and stress-relieve cold-worked parts (~250–300 °C) to avoid ammonia-induced SCC.
What is the maximum service temperature of C33000-O?
C33000-O 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 C33000-O and C33000-H80?
O is the default condition — softest condition — pick for tight-radius bending, expanding, flaring and forming of tube. H80: heavily drawn tube for maximum burst/pressure rating and rigid straight lengths. Yield strength is 110 MPa in O versus 415 MPa in H80.
Can FabDigit make parts in C33000-O?
Yes — C33000-O is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B135 — Seamless Brass Tube — ASTM International (2017)
- CDA Alloy Datasheet C33000 (Low-Leaded Brass Tube) — Copper Development Association (2023)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion of Copper and 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.