Copper Alloy C33000
UNS C33000 · ASTM B135
C33000 is a low-leaded brass of about 66 % copper with 0.25–0.7 % lead, supplied specifically as seamless tube to ASTM B135.
Values for the O condition
C33000 tempers and conditions
C33000 is supplied in 7 conditions, soft to hard. O 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 |
|---|---|---|---|---|---|---|
Light annealed | Light anneal for a balance of formability and handling stiffness in coiled or straight tube. | 105 | 320 | 58 | 50 HB | 26 % IACS |
ODefault Annealed | Softest condition — pick for tight-radius bending, expanding, flaring and forming of tube. | 110 | 340 | 55 | 55 HB | 26 % IACS |
Light drawn | Lightly drawn tube — better straightness and strength than annealed while still bendable. | 200 | 360 | 40 | 85 HB | 26 % IACS |
Drawn, general purpose | Most common as-drawn tube temper for general plumbing/heat-exchanger and machined-fitting stock. | 250 | 390 | 30 | 100 HB | 26 % IACS |
Half hard | Half-hard drawn tube/rod — good compromise of strength, screw-machine performance and moderate forming. | 275 | 420 | 25 | 110 HB | — |
Full hard | Full-hard drawn condition for maximum strength, straightness and best turning finish; little cold forming left. | 390 | 500 | 8 | 145 HB | — |
Hard drawn | Heavily drawn tube for maximum burst/pressure rating and rigid straight lengths. | 415 | 520 | 6 | 155 HB | 26 % IACS |
What is C33000?
C33000 is a low-leaded brass of about 66 % copper with 0.25–0.7 % lead, supplied specifically as seamless tube to ASTM B135. The small lead addition improves turning and punching while preserving cold bending, tube expanding and brazing behaviour; annealed tube gives 340 MPa tensile, 110 MPa yield, 55 % elongation and 55 HB with service to about 200 °C. The lead content excludes it from current drinking-water requirements, ammonia and amine environments cause stress-corrosion cracking, stagnant seawater or acidic water dezincifies it, and fusion welding is poor — joints are normally brazed or soldered. C26000 is the unleaded tube alternative. C33000 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). C33000 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 82% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 103 GPa (14.9 Msi).
What is C33000 used for?
- Heat exchanger and condenser tubes
- Gas and liquid transfer tubing
- Machined tube fittings
- Lighting fixture tubing
- Hardware and decorative tube
- Instrument and gauge lines
Advantages
- Ductile — tolerates forming and impact — 55%, better than 98% of copper alloy grades
- Forms and bends easily — 85/100, better than 85% 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 82% of copper alloy grades
- Difficult to weld — 25/100, worse than 78% of copper alloy grades
C33000 properties
Typical room-temperature values for C33000-O; bars are the position among copper alloy grades.
Physical3
C33000 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).
Mechanical13
C33000 has a yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 82% of copper alloy grades. Elongation at break is 55% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
C33000 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 68% of copper alloy grades. Thermal expansion is 20.2 µm/m·K (11.2 µin/in·°F).
Electrical3
C33000 conducts electricity at 26 % IACS, better than 63% 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 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'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.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C33000 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C33000
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.
Manufacturability
The process limits FabDigit applies to C33000. Every C33000 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Good70 / 100 |
|---|---|
| ISO material group | N.5 |
| Cutting speed (rough / finish) | 180 / 220 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 6× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better85 / 100 |
|---|---|
| Weldability | Fair25 / 100 |
| Bendable | Yes |
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 |
What surface finishes work on C33000?
Polishes to a bright yellow finish; accepts nickel/chrome plating, chemical blackening/antiquing and clear lacquer — no anodizing.
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).
Passivation
Plating
Organic Coating
Equivalent designations
Standards and trade names that resolve to Copper Alloy C33000 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B135
- Also called
- Low-Lead Brass Tube
How much does C33000 cost?
C33000 is a high-cost copper alloy ($$$$), cheaper than about 51% 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.
C33000 — frequently asked
What is C33000 used for?
C33000 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?
C33000 has a typical yield strength of 110 MPa (16 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 82% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C33000 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 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?
Polishes to a bright yellow finish; accepts nickel/chrome plating, chemical blackening/antiquing and clear lacquer — no anodizing.
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 is the maximum service temperature of C33000?
C33000 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.
How much does C33000 cost?
C33000 is a high-cost copper alloy ($$$$), cheaper than about 51% 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.
Can FabDigit make parts in C33000?
Yes — C33000 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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; 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.