Aluminium Brass Tubes are copper-alloy tubes designed for high performance in water-based applications. These tubes are frequently made from UNS C68700 / CuZn20Al2 and supplied to standards like ASTM B111 and ASME SB111, and they are alloyed with aluminum which allows them to form a protective oxide layer on the surface. They are resistant to seawater erosion-corrosion, dezincification, and cooling systems and are used in condensers, heat exchangers, desalination equipment and seawater systems. Aluminium Brass Tubes are especially beneficial when used in situations where seafaring conditions are highly corrosive and harsh, and water flow is fast. Available in seamless construction with various outside diameters, wall thicknesses and lengths of varying equipment requirements. Amardeep Steel Centre LLP is a trusted Aluminium Brass Tubes manufacturer and supplier in India.
Technical Data
Specifications of Aluminium Brass Tubes
Field | Details |
|---|---|
Grade / UNS | C68700 / CuZn20Al2 |
Governing Standards | ASTM B111 / ASME SB111 |
Outer Diameter (OD) | 6.0 mm to 150.0 mm |
Wall Thickness | 0.5 mm to 10.0 mm |
Length | Up to 12 meters, or cut to length per drawing |
Temper Conditions | O60 / F34 (Light Annealed), H / HH / QH (Drawn / Hard) |
Product Forms | Straight Tubes, U-Bend Tubes, Low Fin Tubes |
Chemical Compositions of Aluminium Brass Tubes
Element | Min (%) | Max (%) | Role / Significance |
|---|---|---|---|
Copper (Cu) | 76.0 | 79.0 | Base matrix providing thermal conductivity and ductility |
Aluminum (Al) | 1.8 | 2.5 | Forms the protective surface oxide film against impingement attack |
Arsenic (As) | 0.02 | 0.06 | Inhibits dezincification in saline environments |
Lead (Pb) | — | 0.07 | Tramp element restriction to preserve cold-workability |
Iron (Fe) | — | 0.06 | Impurity limit to maintain optimal corrosion performance |
Zinc (Zn) | Remainder | Remainder | Balance alloy providing mechanical strength |
Aluminium Brass Tubes Physical Properties
Property | Metric Value | Imperial Value |
|---|---|---|
Density | 8.33 g/cm³ | 0.301 lb/in³ |
Melting Range | 930°C – 980°C | 1710°F – 1790°F |
Thermal Conductivity | 100 W/m·K | 58 BTU·in/(hr·ft²·°F) |
Specific Heat Capacity | 0.38 J/g·°C | 0.09 BTU/lb·°F |
Electrical Conductivity | 10% IACS | 10% IACS |
Electrical Resistivity | 17.2 µΩ·cm | 103.5 Ω·circ mil/ft |
Coefficient of Thermal Expansion | 20.5 µm/m·°C (20°C–300°C) | 11.4 µin/in·°F (68°F–572°F) |
Modulus of Elasticity (Tension) | 110 GPa | 16,000 ksi |
Modulus of Rigidity (Shear) | 41 GPa | 6,000 ksi |
Mechanical Properties of Aluminium Brass Tubes
Temper Condition | Temper Designation | Tensile Strength, Min (MPa / ksi) | Yield Strength (0.2% Offset), Min (MPa / ksi) | Elongation in 50 mm, Min (%) | Rockwell Hardness |
|---|---|---|---|---|---|
Light Annealed | O60 / F34 | 360 MPa / 52 ksi | 125 MPa / 18 ksi | 45% | F55 – F75 |
As Drawn / Light Drawn | H / HH | 415 MPa / 60 ksi | 275 MPa / 40 ksi | 15% | B60 – B80 |
Equivalent Grades of Aluminium Brass Tubes
Standard System | Standard Designation / Alloy Grade | Numeric Designation |
|---|---|---|
UNS / ASTM | ASTM B111 C68700 / ASME SB111 UNS C68700 | C68700 |
ISO | CuZn20Al2 | — |
DIN / EN | CuZn20Al2As | 2.0460 / CW702R |
BS (British Standard) | CZ 110 | — |
JIS (Japan) | C 6870 / C 6871 | — |
AFNOR (France) | CuZn20Al2 | — |
GOST (Russia) | LA77-2 | — |
Dimensions and Weight Chart of Aluminium Brass Tubes
Outer Diameter (OD) | Wall Thickness (WT) | Inside Diameter (ID) | Nominal Weight |
|---|---|---|---|
12.70 mm (0.50 in) | 0.89 mm (22 BWG) | 10.92 mm | 0.236 kg/m |
12.70 mm (0.50 in) | 1.24 mm (18 BWG) | 10.22 mm | 0.318 kg/m |
15.88 mm (0.625 in) | 0.89 mm (22 BWG) | 14.10 mm | 0.299 kg/m |
15.88 mm (0.625 in) | 1.24 mm (18 BWG) | 13.40 mm | 0.407 kg/m |
15.88 mm (0.625 in) | 1.65 mm (16 BWG) | 12.58 mm | 0.525 kg/m |
19.05 mm (0.75 in) | 0.89 mm (22 BWG) | 17.27 mm | 0.362 kg/m |
19.05 mm (0.75 in) | 1.24 mm (18 BWG) | 16.57 mm | 0.495 kg/m |
19.05 mm (0.75 in) | 1.65 mm (16 BWG) | 15.75 mm | 0.642 kg/m |
19.05 mm (0.75 in) | 2.11 mm (14 BWG) | 14.83 mm | 0.799 kg/m |
25.40 mm (1.00 in) | 1.24 mm (18 BWG) | 22.92 mm | 0.672 kg/m |
25.40 mm (1.00 in) | 1.65 mm (16 BWG) | 22.10 mm | 0.876 kg/m |
25.40 mm (1.00 in) | 2.11 mm (14 BWG) | 21.18 mm | 1.099 kg/m |
31.75 mm (1.25 in) | 1.65 mm (16 BWG) | 28.45 mm | 1.111 kg/m |
31.75 mm (1.25 in) | 2.11 mm (14 BWG) | 27.53 mm | 1.399 kg/m |
38.10 mm (1.50 in) | 1.65 mm (16 BWG) | 34.80 mm | 1.345 kg/m |
38.10 mm (1.50 in) | 2.11 mm (14 BWG) | 33.88 mm | 1.699 kg/m |
Types of Aluminium Brass Tubes
ASTM B111 C68700 Condenser Tube
.webp "CuZn20Al2 Drawn Tube (DIN 1785)")
CuZn20Al2 Drawn Tube (DIN 1785)
Heavy Wall C68700 Pipe-1
Heavy Wall C68700 Pipe
Inhibited Aluminium Brass Tube
Low Fin Aluminium Brass Tube
SB 111 C68700 Heat Exchanger Tube
Seamless Aluminium Brass Tube
U-Bend Aluminium Brass Tube
Aluminium Brass Tubes in C68700 (CuZn20Al2) to ASTM B111. Seamless and welded, with dimension chart, mechanical properties and mill test certificates.
Request a QuoteApplications and Industrial Uses of Aluminium Brass Tubes
- Marine Condensers
- Power Plant Heat Exchangers
- Seawater Cooling Systems
- Desalination Plants
- Shipboard Heat Exchangers
- Coastal Power Station Cooling Equipment
- Oil Refinery Heat Exchangers
- Industrial Water-Cooled Condensers
Frequently Asked Questions
What is C68700 Aluminium Brass Tube?
C68700 Aluminium Brass Tube is a seamless copper-zinc-aluminum alloy tube engineered for seawater cooling systems. The presence of roughly 2% aluminum forms a protective oxide skin that protects against high-velocity seawater erosion.
What is the difference between Aluminium Brass and Admiralty Brass?
Aluminium Brass (C68700) contains aluminum to handle seawater velocities up to 2.5–3.0 m/s. Admiralty Brass (C44300) uses tin instead of aluminum and is intended for lower flow velocities (up to 1.8 m/s) or less aggressive water conditions.
What standards govern Aluminium Brass tube manufacturing?
The primary standards are ASTM B111 and ASME SB111 (UNS C68700). International equivalents include DIN EN 12451 / 12492 (CW702R / 2.0460) and BS 2871 CZ110.
What tube sizes are available?
Standard outer diameters range from 6.0 mm to 150.0 mm with wall thicknesses from 0.5 mm to 10.0 mm (including common BWG gauges like 16, 18, and 22). Straight lengths up to 12 meters and custom U-bends are supplied to order.
What testing certifications accompany these tubes?
Tubes ship with EN 10204 3.1 Material Test Certificates covering chemical analysis, mechanical testing, 100% Eddy Current Test (ECT) results, hydrostatic test results, and stress corrosion test compliance. Third-party inspection (EN 10204 3.2) is available upon request.
Can Aluminium Brass Tube be supplied with fins or as U-bends?
Yes. Tubes are supplied in straight lengths, precision-bent U-tubes with stress-relieved bend areas, or enhanced surfaces such as low-fin profiles for improved thermal efficiency.
