Copper Alloy C38500
UNS C38500 · ASTM B455 · EN CuZn39Pb3, CW608N
C38500 is a leaded α+β copper-zinc alloy (about 57Cu-40Zn-3Pb) to ASTM B455 and CW608N, known in the trade as architectural bronze and supplied mainly as hot-extruded bar, shapes and window and door frame sections.
Values for the As Extruded condition
C38500 tempers and conditions
C38500 is supplied in 5 conditions, soft to hard. As Extruded is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Soft annealed | Choose when maximum ductility for light bending or crimping of extruded sections is needed. | 130 | 380 | 40 | 85 HB | 27 % IACS |
As ExtrudedDefault hot extruded / hot rolled, no cold work | Standard supply condition for architectural shapes, door/window sections and general machined parts. | 170 | 415 | 30 | 100 HB | 27 % IACS |
Quarter hard | Light draw for improved straightness, size tolerance and surface on rod without losing much ductility. | 250 | 440 | 22 | 115 HB | 26 % IACS |
Half hard | Cold-drawn condition for CNC turning stock and load-bearing hardware needing higher yield strength. | 340 | 470 | 15 | 130 HB | — |
Full hard | Maximum strength and stiffness for small-diameter rod, wire and screw stock; very limited bending. | 415 | 540 | 8 | 150 HB | 26 % IACS |
What is C38500?
C38500 is a leaded α+β copper-zinc alloy (about 57Cu-40Zn-3Pb) to ASTM B455 and CW608N, known in the trade as architectural bronze and supplied mainly as hot-extruded bar, shapes and window and door frame sections. It is chosen for its combination of hot extrudability, a machinability rating of about 90% of free-cutting C36000, and a gold surface that polishes and patinates well, with 170 MPa yield, 415 MPa tensile, 100 HB and 27% IACS. The limits are poor cold formability (rating 30) and poor fusion weldability, lead content restricted by RoHS and potable-water rules, service limited to about 200 °C, and dezincification or stress-corrosion cracking in ammonia or stagnant seawater. C38500 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 875°C (1,607 °F). C38500 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 62% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 97 GPa (14.1 Msi).
What is C38500 used for?
- Architectural extrusions
- Decorative trims
- Hinges
Advantages
- Easy to machine — 90/100, better than 98% of copper alloy grades
- Polishes to a fine finish — 85/100, better than 92% of copper alloy grades
- Ductile — tolerates forming and impact — 30%, better than 75% of copper alloy grades
Limitations
- Low stiffness — 97 GPa (14.1 Msi), worse than 88% of copper alloy grades
- Difficult to weld — 20/100, worse than 88% of copper alloy grades
C38500 properties
Typical room-temperature values for C38500-As Extruded; bars are the position among copper alloy grades.
Physical3
C38500 has a density of 8.47 g/cm³ (0.306 lb/in³), lighter than 68% of copper alloy grades. It melts at 875°C (1,607 °F).
Mechanical14
C38500 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 62% of copper alloy grades. Elongation at break is 30% and the elastic modulus is 97 GPa (14.1 Msi).
Thermal6
C38500 is rated for continuous service to 200°C (392 °F). It conducts heat at 123 W/m·K (71.1 BTU/hr·ft·°F), better than 70% of copper alloy grades. Thermal expansion is 20.9 µm/m·K (11.6 µin/in·°F).
Electrical3
C38500 conducts electricity at 27 % IACS, better than 67% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 86% of copper alloy grades.
Sustainability4
Producing a kilogram of C38500 takes about 55 MJ of energy and emits 3.6 kg of CO₂ — less than 72% of copper alloy grades. Typical recycled content is 80%.
Manufacturability8
C38500's machinability is excellent (90/100, better than 98% of copper alloy grades); weldability poor (20/100); formability poor (30/100).
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. C38500 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C38500
Is C38500 easy to machine?
Outstanding free-machining behaviour: high speeds, 0° to slightly negative rake, chip-breaking lead phase, minimal tool wear — a benchmark alloy for high-volume turning.
Can C38500 be welded?
Not recommended for fusion welding (lead embrittles the weld); join by soft soldering or silver brazing with low-heat input, or use mechanical fasteners.
Can C38500 be formed, bent or molded?
Excellent hot extrusion and hot forging (650–750 °C); cold bending/forming is poor — design for extruded profiles rather than cold work.
Manufacturability
The process limits FabDigit applies to C38500. Every C38500 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Excellent90 / 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 |
C38500 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 |
|---|---|---|
| CuCuZn39Pb3/CW614N is narrower: 57.0–59.0 | 55 – 59 | 57 |
| Pbfree-machining phase | 2.5 – 3.5 | 3 |
| Fe | ≤ 0.35 | |
| Znremainder, nominally ~40% | balance |
What surface finishes work on C38500?
Buffs to a bright gold colour; commonly given statuary/oxidized chemical finishes, satin brushing plus clear lacquer, or Ni/Cr/PVD plating — 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 C38500 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B455
- EN / DIN / Werkstoff-Nr.
- CuZn39Pb3CW608N
- Trade names
- Messing
- Also called
- Architectural BronzeExtruded Brass
How much does C38500 cost?
C38500 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.
C38500 — frequently asked
What is C38500 used for?
C38500 is typically used for architectural extrusions, decorative trims and hinges. In short: decorative brass; golden finish.
What is the yield strength of C38500?
C38500 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — weaker than 62% of copper alloy grades. Strength varies by condition: see the 5 listed tempers.
Is C38500 easy to machine?
Yes — machinability is rated excellent (90/100, better than 98% of copper alloy grades). Outstanding free-machining behaviour: high speeds, 0° to slightly negative rake, chip-breaking lead phase, minimal tool wear — a benchmark alloy for high-volume turning.
Can C38500 be welded?
Not readily — weldability is rated poor (20/100). Not recommended for fusion welding (lead embrittles the weld); join by soft soldering or silver brazing with low-heat input, or use mechanical fasteners.
What surface finishes work on C38500?
Buffs to a bright gold colour; commonly given statuary/oxidized chemical finishes, satin brushing plus clear lacquer, or Ni/Cr/PVD plating — no anodizing.
Can C38500 be formed, bent or molded?
Excellent hot extrusion and hot forging (650–750 °C); cold bending/forming is poor — design for extruded profiles rather than cold work.
What is the maximum service temperature of C38500?
C38500 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 C38500 As Extruded and C38500-H04?
As Extruded is the default condition — standard supply condition for architectural shapes, door/window sections and general machined parts. H04: maximum strength and stiffness for small-diameter rod, wire and screw stock; very limited bending. Yield strength is 170 MPa in As Extruded versus 415 MPa in H04.
How much does C38500 cost?
C38500 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 C38500?
Yes — C38500 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B455 — Copper Alloy (UNS C38000/C38500) Extruded Shapes and Bars — ASTM (2020)
- EN 12164/12165 — Copper and copper alloys, rod and forging stock (CW614N, CuZn39Pb3) — CEN (2016)
- C38500 Architectural Bronze alloy datasheet — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.