C38500 — Architectural Bronze
Our Products
Our Brochure
C38500 — Architectural Bronze Brochure
Download
Descriptions
C38500, commonly known as Architectural Bronze, is a versatile leaded brass alloy primarily composed of copper and zinc, with a controlled addition of lead to improve machinability. It offers a rich golden-brown color, excellent surface finish, and good strength—making it a preferred material for architectural, decorative, and hardware applications where both aesthetics and functionality are essential.
The alloy’s combination of moderate strength, superior machinability, and corrosion resistance makes it particularly suitable for complex shapes, extrusions, and profiles that require precision fabrication and an attractive appearance. C38500 is widely used for extruded products such as door frames, window sections, railings, locks, hinges, handles, and decorative trims. Its warm bronze tone deepens naturally with exposure, developing an elegant patina highly valued in architectural design.
Due to its excellent workability and polish retention, C38500 Architectural Bronze is extensively used by manufacturers of hardware fittings, ornamental works, and structural decorative elements. It is also employed in electrical and plumbing applications where moderate conductivity and corrosion resistance are required.
Key Attributes:
- Excellent machinability (rated about 90% of free-cutting brass)
- Good strength and wear resistance
- Attractive golden-bronze color with superior polishability
- Excellent hot formability and extrusion characteristics
- Good corrosion resistance in atmospheric and mild industrial environments
Applications include: architectural profiles, extrusions, curtain wall sections, ornamental grills, window and door frames, locks, hinges, and decorative fittings.
Chemical Composition
C38500 Architectural Bronze is a leaded brass alloy that combines copper and zinc with a controlled amount of lead to enhance machinability and extrusion performance. The composition ensures a balance of strength, surface finish, and corrosion resistance ideal for architectural and decorative components.
| Element | Weight % |
|---|---|
| Copper (Cu) | 55.0 – 59.0% |
| Zinc (Zn) | Balance |
| Lead (Pb) | 2.5 – 3.5% |
| Iron (Fe) | ≤ 0.35% |
Note: Total Copper plus all named alloying elements ≥ 99.5%.
Mechanical, Physical & Fabrication Properties
At room temperature, C38500 Architectural Bronze offers a well-balanced combination of strength, ductility, and excellent machinability — ideal for extruded sections and architectural components.
| Property | Metric | Imperial | Remarks |
|---|---|---|---|
| Tensile Strength | ≈ 300 MPa | ≈ 43,500 psi | Moderate strength for extruded and shaped products |
| Yield Strength | ≈ 150 MPa | ≈ 21,750 psi | Provides adequate rigidity for structural profiles |
| Elongation at Break | ≈ 25% | — | Ensures good formability and ductility |
| Brinell Hardness | ≈ 60 HB | — | Offers moderate wear and impact resistance |
| Machinability Rating | Excellent (≈ 90% of Free-Cutting Brass C36000) | Ideal for precision machining and extrusion | |
Physical Properties
| Property | Metric | Imperial | Remarks |
|---|---|---|---|
| Density | 8.5 g/cm³ | 0.307 lb/in³ | High density for solid, rigid components |
| Electrical Conductivity | ≈ 15% IACS | — | Moderate conductivity suitable for hardware applications |
| Thermal Conductivity | ≈ 120 W/m·K | ≈ 69 BTU/ft·hr·°F | Good heat dissipation in architectural and industrial parts |
| Coefficient of Thermal Expansion | ≈ 19 × 10⁻⁶ /°C | — | Stable performance across temperature variations |
| Melting Point (Liquidus) | ≈ 900°C | ≈ 1,650°F | — |
| Melting Point (Solidus) | ≈ 840°C | ≈ 1,545°F | — |
These mechanical and physical properties make C38500 the alloy of choice for architectural fittings, extrusions, and hardware where durability, finish quality, and workability are equally important.
Applications
C38500 Architectural Bronze is widely used across multiple industries where strength, machinability, and corrosion resistance are equally important. Its attractive golden hue and excellent surface finish also make it a popular choice for decorative and architectural purposes.
- Architectural Components: Storefront systems, thresholds, trim, hinges, lock bodies, door frames, and other forged or extruded fittings.
- Marine Applications: Components exposed to seawater and brine environments such as hardware, couplings, and valve parts.
- Industrial Equipment: Machined parts requiring a combination of high machinability, wear resistance, and moderate strength, such as bushings, bearings, and connectors.
Its excellent machinability, corrosion resistance, and formability make C38500 one of the most versatile and cost-effective alloys for both decorative and functional applications.
Standards & International Equivalents:
| Standard Organization | Designation | Description / Notes |
|---|---|---|
| UNS | C38500 | Unified Numbering System designation |
| ASTM | B21, B22, B43 | Standard specifications for brass bars, rods, and shapes used in architectural and industrial applications |
| BS | 2874 CZ121 | British Standard equivalent for free-machining brass |
| ISO | CuZn39Pb3 | International standard equivalent under ISO system |
These international standards and equivalents ensure consistent quality and interchangeability of C38500 Architectural Bronze across global markets.
Common Names & International Identifiers
| Category | Designation / Description |
|---|---|
| Common Names | Architectural Bronze |
| Trade Designations | UNS C38500, ASTM B21, ASTM B22, ASTM B43 |
| CDA Alloy Number | 385 |
C38500 is also widely referred to as Architectural Bronze due to its excellent surface finish, machinability, and warm golden color — making it a preferred material for architectural fittings, hardware, and extrusions.
Common Product Forms & Dimensions
Round Rod Sizes
| Rod Diameter (Inches) | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|
| 1/4 | 0.2 | 2.9 |
| 3/8 | 0.4 | 6.5 |
| 1/2 | 0.7 | 11.6 |
| 5/8 | 1.1 | 18.1 |
| 3/4 | 1.6 | 26.1 |
| 1 | 2.9 | 46.2 |
| 1¼ | 4.5 | 72.3 |
| 1½ | 6.5 | 104.2 |
| 2 | 11.6 | 185.1 |
Square Rod Sizes
| Square Size (Inches) | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|
| 1/4 | 0.2 | 3.7 |
| 3/8 | 0.5 | 8.3 |
| 1/2 | 0.9 | 14.7 |
| 5/8 | 1.4 | 23.0 |
| 3/4 | 2.1 | 33.1 |
| 1 | 3.7 | 58.9 |
| 1¼ | 5.8 | 92.2 |
| 1½ | 8.3 | 132.6 |
| 2 | 14.7 | 235.8 |
Rectangle Bar Sizes — Weight Table (C38500)
| Set A | Set B | Set C | ||||||
|---|---|---|---|---|---|---|---|---|
| Bar Size (T × W) in | lbs/ft | lbs/16 ft | Bar Size (T × W) in | lbs/ft | lbs/16 ft | Bar Size (T × W) in | lbs/ft | lbs/16 ft |
| 1/8 × 1/2 | 0.23 | 3.7 | 1/4 × 1/2 | 0.46 | 7.4 | 1/2 × 3/4 | 1.38 | 22.1 |
| 1/8 × 5/8 | 0.29 | 4.6 | 1/4 × 5/8 | 0.58 | 9.2 | 1/2 × 1 | 1.84 | 29.4 |
| 1/8 × 3/4 | 0.35 | 5.5 | 1/4 × 3/4 | 0.69 | 11.1 | 1/2 × 1 1/4 | 2.30 | 36.8 |
| 1/8 × 1 | 0.46 | 7.4 | 1/4 × 1 | 0.92 | 14.7 | 1/2 × 1 1/2 | 2.76 | 44.2 |
| 1/8 × 1 1/4 | 0.58 | 9.2 | 1/4 × 1 1/4 | 1.15 | 18.4 | 1/2 × 2 | 3.68 | 58.9 |
| 1/8 × 1 1/2 | 0.69 | 11.1 | 1/4 × 1 1/2 | 1.38 | 22.1 | 1/2 × 2 1/2 | 4.60 | 73.6 |
| 1/8 × 2 | 0.92 | 14.7 | 1/4 × 2 | 1.84 | 29.4 | 1/2 × 3 | 5.48 | 87.7 |
| 1/8 × 2 1/2 | 1.15 | 18.4 | 1/4 × 2 1/2 | 2.31 | 37.0 | 1/2 × 4 | 7.37 | 117.9 |
| 1/8 × 3 | 1.38 | 22.1 | 1/4 × 3 | 2.76 | 44.2 | 1/2 × 6 | 11.06 | 177.0 |
| 1/8 × 4 | 1.84 | 29.4 | 1/4 × 4 | 3.65 | 58.4 | — | — | — |
| — | — | — | 1/4 × 6 | 5.52 | 88.3 | 3/4 × 1 | 2.76 | 44.2 |
| 3/16 × 1/2 | 0.35 | 5.5 | — | — | — | 3/4 × 1 1/4 | 3.46 | 55.4 |
| 3/16 × 5/8 | 0.43 | 6.9 | 3/8 × 1/2 | 0.69 | 11.1 | 3/4 × 1 1/2 | 4.14 | 66.2 |
| 3/16 × 3/4 | 0.52 | 8.3 | 3/8 × 5/8 | 0.86 | 13.8 | 3/4 × 2 | 5.53 | 88.5 |
| 3/16 × 1 | 0.69 | 11.1 | 3/8 × 3/4 | 1.04 | 16.6 | 3/4 × 2 1/2 | 6.90 | 110.4 |
| 3/16 × 1 1/4 | 0.86 | 13.8 | 3/8 × 1 | 1.38 | 22.1 | 3/4 × 3 | 8.29 | 132.6 |
| 3/16 × 1 1/2 | 1.04 | 16.6 | 3/8 × 1 1/4 | 1.73 | 27.7 | 3/4 × 4 | 11.1 | 176.8 |
| 3/16 × 2 | 1.38 | 22.1 | 3/8 × 1 1/2 | 2.07 | 33.1 | 3/4 × 6 | 16.6 | 264.8 |
| 3/16 × 2 1/2 | 1.73 | 27.7 | 3/8 × 2 | 2.76 | 44.2 | — | — | — |
| 3/16 × 3 | 2.07 | 33.1 | 3/8 × 2 1/2 | 3.45 | 55.2 | 1 × 1 1/4 | 4.6100 | 73.8 |
| 3/16 × 4 | 2.76 | 44.2 | 3/8 × 3 | 5.48 | 87.7 | 1 × 1 1/2 | 5.5500 | 88.8 |
| — | — | — | 3/8 × 4 | 5.53 | 88.5 | 1 × 2 | 7.3700 | 117.9 |
| — | — | — | 3/8 × 6 | 8.30 | 132.8 | 1 × 2 1/2 | 9.2000 | 147.2 |
| — | — | — | — | — | — | 1 × 3 | 11.0500 | 176.8 |
| — | — | — | — | — | — | 1 × 4 | 14.7600 | 236.2 |
| — | — | — | — | — | — | 1 × 6 | 22.1100 | 353.8 |
Square Tube Sizes
| Square Tube (A × B) | Wall Thickness (T) in | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|---|
| 1/2 × 1/2 | 0.093 | 0.586 | 9.38 |
| 5/8 × 5/8 | 0.093 | 0.756 | 12.10 |
| 3/4 × 3/4 | 0.093 | 0.929 | 14.86 |
| 1 × 1 | 0.100 | 1.360 | 21.76 |
| 1 × 1 | 0.125 | 1.660 | 26.56 |
| 1¼ × 1¼ | 0.100 | 1.730 | 27.68 |
| 1½ × 1½ | 0.100 | 2.090 | 33.44 |
| 1½ × 1½ | 0.125 | 2.580 | 41.28 |
| 1¾ × 1¾ | 0.100 | 2.460 | 39.36 |
| 2 × 2 | 0.100 | 2.840 | 45.44 |
| 2 × 2 | 0.125 | 3.510 | 56.16 |
| 2½ × 2½ | 0.100 | 3.480 | 55.68 |
| 2½ × 2½ | 0.125 | 4.430 | 70.88 |
| 3 × 3 | 0.125 | 5.350 | 85.60 |
Note: Square tubes can be supplied in standard or custom lengths, with tighter tolerances or special finishes (mill, polished, or brushed) upon request.
Angle Equal Leg Sizes
| Equal Legs Angle (A × B) | Wall Thickness (T) in | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|---|
| 1/4 × 1/4 | 0.062 | 0.12 | 1.86 |
| 3/8 × 3/8 | 0.062 | 0.17 | 2.64 |
| 3/8 × 3/8 | 0.093 | 0.22 | 3.52 |
| 3/8 × 3/8 | 0.125 | 0.30 | 4.80 |
| 1 × 1½ | 0.062 | 0.23 | 3.70 |
| 1/2 × 1/2 | 0.093 | 0.31 | 4.96 |
| 1/2 × 1/2 | 0.125 | 0.42 | 6.72 |
| 5/8 × 5/8 | 0.062 | 0.29 | 4.58 |
| 5/8 × 5/8 | 0.093 | 0.36 | 5.76 |
| 5/8 × 5/8 | 0.125 | 0.52 | 8.32 |
| 3/4 × 3/4 | 0.062 | 0.35 | 5.63 |
| 3/4 × 3/4 | 0.093 | 0.48 | 7.68 |
| 3/4 × 3/4 | 0.125 | 0.64 | 10.24 |
| 1 × 1 | 0.062 | 0.484 | 7.74 |
| 1 × 1 | 0.093 | 0.69 | 11.04 |
| 1 × 1 | 0.125 | 0.89 | 14.24 |
| 1 × 1 | 0.187 | 1.36 | 21.76 |
| 1 × 1 | 0.25 | 1.60 | 25.60 |
| 1¼ × 1¼ | 0.062 | 0.55 | 8.80 |
| 1¼ × 1¼ | 0.093 | 0.82 | 13.12 |
| 1¼ × 1¼ | 0.125 | 1.09 | 17.44 |
| 1¼ × 1¼ | 0.187 | 1.60 | 25.60 |
| 1¼ × 1¼ | 0.25 | 2.05 | 32.80 |
| 1¼ × 1½ | 0.125 | 1.35 | 21.60 |
| 1¼ × 1½ | 0.187 | 1.92 | 30.72 |
| 1¼ × 1½ | 0.25 | 2.52 | 40.32 |
| 2 × 2 | 0.25 | 1.79 | 28.64 |
| 2 × 2 | 0.187 | 2.61 | 41.76 |
| 2 × 2 | 0.25 | 3.37 | 53.92 |
| 2½ × 2½ | 0.125 | 2.17 | 34.72 |
| 2½ × 2½ | 0.25 | 4.35 | 69.60 |
| 3 × 3 | 0.125 | 2.63 | 42.08 |
| 3 × 3 | 0.25 | 5.25 | 84.00 |
Note: Equal leg angles are supplied in mill or custom-cut lengths (up to 16 ft). Special tempers, finishes, or profiles can be produced as per customer specifications.
Angle Unequal Leg Sizes
| Unequal Legs Angle (A × B) | Wall Thickness (T) in | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|---|
| 3/8 × 3/4 | 0.125 | 0.45 | 7.20 |
| 1/2 × 3/4 | 0.125 | 0.52 | 8.32 |
| 1/2 × 1 | 0.062 | 0.33 | 5.22 |
| 1/2 × 1 | 0.125 | 0.65 | 10.40 |
| 1/2 × 1½ | 0.125 | 0.84 | 13.44 |
| 1/2 × 2 | 0.125 | 1.09 | 17.44 |
| 3/4 × 1 | 0.125 | 0.75 | 12.00 |
| 3/4 × 1¼ | 0.125 | 0.88 | 14.08 |
| 3/4 × 1½ | 0.125 | 0.97 | 15.52 |
| 1 × 1½ | 0.125 | 1.10 | 17.60 |
| 1 × 2 | 0.125 | 1.33 | 21.28 |
| 2 × 3 | 0.125 | 2.20 | 35.20 |
Note: Unequal leg angles are supplied in standard mill or custom-cut lengths up to 16 feet. Special tempers, surface finishes, and custom dimensions can be produced upon request.
Channel Sizes
| Equal Legs Channel (A × B × C) | Wall Thickness (T) in | Weight (lbs/ft) | Approx. Weight (lbs/16 ft) |
|---|---|---|---|
| 1/4 × 1/4 × 1/4 | 0.040 | 0.12 | 1.92 |
| 3/8 × 3/8 × 3/8 | 0.062 | 0.26 | 4.16 |
| 1/2 × 1/2 × 1/2 | 0.062 | 0.30 | 4.80 |
| 1/2 × 1/2 × 1/2 | 0.093 | 0.45 | 7.20 |
| 5/8 × 5/8 × 5/8 | 0.093 | 0.60 | 9.60 |
| 3/4 × 3/4 × 3/4 | 0.093 | 0.68 | 10.88 |
| 3/4 × 3/4 × 3/4 | 0.125 | 0.90 | 14.40 |
| 1 × 1 × 1 | 0.093 | 0.93 | 14.88 |
| 1 × 1 × 1 | 0.125 | 1.60 | 20.00 |
| 1¼ × 1¼ × 1¼ | 0.125 | 1.60 | 25.60 |
| 1½ × 1½ × 1½ | 0.125 | 1.94 | 31.04 |
| 2 × 2 × 2 | 0.125 | 2.60 | 41.60 |
Note: Channels are supplied in mill or custom-cut lengths (up to 16 feet). Special sizes, tempers, or surface finishes can be manufactured on request.
Handrail Moulding Sizes
| Handrail Moulding (A) | (B) | (C) | Approx. Weight (lbs/ft) |
|---|---|---|---|
| 1 5/8 | 1 1/16 | 5/8 | 1.84 |
| 1 15/16 | 1 5/16 | 1 1/16 | 2.56 |
| 2 1/4 | 1 9/16 | 1 5/16 | 3.12 |
Note: Handrail mouldings are supplied in standard or custom lengths (typically up to 16 feet). Profiles can be polished, brushed, or finished to architectural specifications upon request.
Tell Us What You Need
30+
Years of Experience
Trusted Worldwide | Supplying Copper & Alloys to 1000+ clients
We usually respond within 24 working hours.