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Products Description
Condenser tubes made from ASTM B111 UNS C68700 (also known as "aluminum brass") offer excellent corrosion and erosion resistance, thermal conductivity, and mechanical properties, making them ideal for a variety of heat exchange applications. UNS C68700 is an alloy with a nominal content of 77.5% copper, 2% aluminum, and 20.5% zinc, with a trace amount of arsenic (0.04%) added as an inhibitor. Brass is essentially a copper-zinc alloy. The aluminum addition binds aluminum oxide, a key component of the corrosion film, to the brass, significantly improving its resistance to impact corrosion in turbulent, high-velocity saltwater. Trace amounts of arsenic are added to aluminum brass to "inhibit" its susceptibility to dezincification. Consequently, tubes made from ASTM B111 UNS C68700 arsenic-aluminum brass are frequently used in marine condensers and heat exchangers, where impact corrosion from high-velocity cooling water can be a serious problem.
The chemical composition requirements for ASTM B111 UNS C68700 are as follows:
Copper (Cu): 76.0~79.0%
Aluminum (Al): 1.8~2.5%
Iron (Fe): ≤ 0.06%
Lead (Pb): ≤ 0.07%
Arsenic (As): 0.02~0.06%
Zinc (Zn): Balance
Mechanical Properties
The ASTM B111 UNS C68700 seamless tubes shall be furnished in annealed condition with the temper designation of O61:
Tensile strength: ≥ 50 ksi [345 MPa];
Yield strength: ≥ 18 ksi [125 MPa];
Elongation: ≥ 55%;
Machinability rating: 30%.
International Equivalent & Annealing Temperature
The arsenical aluminum brass ASTM B111 UNS C68700 has several international equivalent grades: HAL77-2 (China), CZ110 (BS), CuZn20Al2 (DIN), C6870 (JIS H). The tubes shall be bright annealed at a temperature between 425°C [800°F] and 600°C [1100°F].
Products provided by GNEE
| Product Category | Standard & Material | Available Forms | Thickness / Diameter Range | Width / OD Range | Length / Form | Temper / State | Surface Finish |
|---|---|---|---|---|---|---|---|
| Copper Sheet & Plate | ASTM B152, B187 Pure Copper (C11000) Phosphor Bronze, Brass |
• Coil • Sheet • Plate |
Sheet: 0.3 mm - 10.0 mm Plate: 10.0 mm - 100 mm |
100 mm - 2500 mm | Coil: Custom Sheet/Plate: 1000mm - 6000mm or Custom |
• O (Soft Annealed) • H02 (Half-Hard) • H04 (Hard) • H08 (Full-Hard) |
• Mill (Bare) • Clad • Brushed • Coated |
| Copper Rod & Bar | ASTM B133, B187 Pure Copper, Tellurium Copper Brass, Bronze |
• Round Rod • Square Bar • Hexagonal Bar • Flat Bar |
Rod Dia.: 2.0 mm - 300 mm Flat Bar Thk.: 3 mm - 50 mm |
Flat Bar Width: 10 mm - 400 mm | Straight: 1000mm - 6000mm Coil (for small dia.) |
• Annealed (Soft) • Half-Hard • Hard • As Drawn |
• Drawn (Smooth) • Turned (Peeled) • Ground (Polished) |
| Copper Wire | ASTM B1, B3 Bare Copper, Tinned Copper |
• Bare Wire • Tinned Wire • Stranded Wire • Braided Wire |
Solid Wire: 0.05 mm - 10.0 mm Stranded: Custom (e.g., 7/0.2mm) |
- | Coil, Spool, Reel Weight: Custom (e.g., 5kg, 25kg) |
• Soft (Annealed) • Hard Drawn • Medium-Hard |
• Bright Bare • Electrotinned • Oxidized-Resistant |
| Copper Tube & Pipe | ASTM B75, B88 Seamless, Welded DHP Copper (C12200) |
• Straight Tube • Coiled Tube • Capillary Tube • Square Tube |
OD: 3 mm - 300 mm Wall Thk.: 0.5 mm - 10.0 mm |
- | Straight: 1000mm - 8000mm Coil: Custom Length |
• Annealed (Soft, Bendable) • Hard Drawn (Straight) |
• Bare (Clean) • Polished • Plastic Capped |
| Copper Foil | ASTM B370 Rolled Annealed (RA) Electrodeposited (ED) |
• Roll / Coil • Strip |
Thickness: 0.01 mm - 0.50 mm (10 µm - 500 µm) |
10 mm - 1300 mm | Coil: Custom Length | • As Rolled (Hard) • Annealed (Soft, Ductile) • Laminated |
• Standard (One Side Bright) • Double Side Bright • Treated (for PCB) |
