GNEE is a manufacturer and supplier of C68700 Aluminum Brass Pipes as per ASTM B111 at competitive prices. We supply aluminum brass seamless tubes with 0.50 to 10.0 mm wall thickness in various sizes.
ASTM B111 is the standard specification for copper and copper-alloy seamless condenser tubes and ferrule stock up to 3-1/8 in. [80 mm] inclusive in diameter, for use in surface condensers, evaporators, and heat exchangers.
Customer Visit & Project Reference – India
We successfully supplied ASTM B111 C68700 aluminum brass tubes to a customer in India for shell & tube condenser applications. During the project, the customer visited our facility for production inspection and quality verification. All tubes were manufactured in accordance with ASTM B111 requirements and delivered with complete Material Test Certificates (MTC), ensuring full heat number traceability and verified chemical and mechanical properties.
C68700 Aluminum Brass Tubes Price List
| Size | Price (USD) |
|---|---|
| Outer Dia 3/4 inch, Wall 25 swg, Pack of 1 | $10.69 |
| 11mm OD x 0.80mm (avg) WT x 6950mm length | $10.62 |
| 11mm OD x 0.80mm (avg) WT x 7500mm length | $10.71 |
| 11mm OD x 0.80mm (avg) WT x 6750mm length | $10.74 |
C68700 Aluminum Brass Pipe Specifications
| Parameter | Range / Details |
|---|---|
| Standard | ASTM B111 / ASME SB111 |
| UNS Number | C68700 |
| Outside Diameter | 4.76mm – 104.78mm |
| Wall Thickness | 0.508mm min (up to 10mm) |
| Length | Max 15 meters straight length |
| Temper | HH, H, O, QH, O61 |
| Cut Length | Double Random, Single Random, Cut Length |
| Type | Heat Exchanger / Seamless / Condenser Tubes |
| Forms | Square, Round, Hydraulic, Rectangular |
| Standards | ASTM B111, ASME B111, BS 2871 Part 3, JIS H3300, DIN 1785, NFA 51 102, IS 1545 |
| Grades | C68700, C60800, C61300 |
ASTM B111 Standard
ASTM B111 / B111M establishes requirements for seamless tube and ferrule stock of copper and various copper alloys. Key requirements include:
| Requirement | Specification |
|---|---|
| Diameter range | Up to 3-1/8 in. [80 mm] inclusive |
| Applications | Surface condensers, evaporators, heat exchangers |
| Manufacturing | Casting, extrusion, drawing, annealing, straightening |
| Chemical composition | Per Table 1 of ASTM B111 |
| Tensile requirements | Per Table 2 (inch-pound) or Table 3 (SI) |
| Grain size (annealed) | 0.010 – 0.045 mm per E112 |
| Expansion test | 20% minimum per B153 |
| Nondestructive testing | Eddy current per E243 |
Chemical Composition – C68700
| Element | Weight % |
|---|---|
| Copper (Cu) | 76.0 – 79.0 |
| Aluminum (Al) | 1.8 – 2.5 |
| Arsenic (As) | 0.02 – 0.06 |
| Lead (Pb) | 0.07 max |
| Iron (Fe) | 0.06 max |
| Zinc (Zn) | Remainder |
Mechanical Properties – C68700
| Property | Value (O61 Temper) |
|---|---|
| Tensile Strength (min) | 345 MPa (50 ksi) |
| Yield Strength (min) | 125 MPa (18 ksi) |
| Grain Size | 0.010 – 0.045 mm |
| Expansion Requirement | 20% of OD |
Physical Properties – CuZn20Al2 Tubes
| Property | Value |
|---|---|
| Density | 0.301 lb/in³ at 68°F (8.33 g/cm³) |
| Thermal Conductivity | 58.0 BTU·in/hr·ft²·°F @ 68°F |
| Coefficient of Thermal Expansion | 10.3 × 10⁻⁶ /°F (68-572°F) |
| Electrical Conductivity | 23% IACS @ 68°F |
| Electrical Resistivity | 45.1 ohms-cmil/ft @ 68°F |
| Modulus of Elasticity | 16000 ksi |
| Modulus of Rigidity | 6000 ksi |
| Specific Gravity | 8.33 |
| Specific Heat Capacity | 0.09 Btu/lb/°F @ 68°F |
| Melting Point (Solidus) | 1710°F |
| Melting Point (Liquidus) | 1780°F |
Size Chart – C68700 Seamless Tubes
| Wall Thickness (mm) | WT/Metre | Metric OD (mm) | Wall Thickness Gauge | Imperial OD | Nominal Bore (mm) |
|---|---|---|---|---|---|
| 1.63 | 0.206 | 6.35 | 16G | 1/4″ | 3.09 |
| 0.71 | 0.077 | 4.76 | 22G | 3/16″ | 3.34 |
| 1.22 | 0.167 | 6.35 | 18G | 1/4″ | 3.91 |
| 0.91 | 0.172 | 7.94 | 20G | 5/16″ | 6.11 |
| 1.63 | 0.345 | 9.52 | 16G | 3/8″ | 6.26 |
| 1.22 | 0.271 | 9.52 | 18G | 3/8″ | 7.08 |
| 1.63 | 0.484 | 12.7 | 16G | 1/2″ | 9.44 |
| 1.22 | 0.375 | 12.7 | 18G | 1/2″ | 10.26 |
| 0.91 | 0.288 | 12.7 | 20G | 1/2″ | 10.88 |
| 1.63 | 0.761 | 19.05 | 16G | 3/4″ | 15.79 |
| 1.22 | 0.583 | 19.05 | 18G | 3/4″ | 16.61 |
| 0.91 | 0.442 | 19.05 | 20G | 3/4″ | 17.23 |
| 1.63 | 1.038 | 25.4 | 16G | 1″ | 22.14 |
| 1.22 | 0.791 | 25.4 | 18G | 1″ | 22.96 |
| 1.63 | 1.316 | 31.75 | 16G | 1-1/4″ | 28.49 |
| 1.63 | 1.593 | 38.1 | 16G | 1-1/2″ | 34.84 |
| 3.25 | 3.040 | 38.1 | 10G | 1-1/2″ | 31.60 |
| 3.25 | 4.140 | 50.8 | 10G | 2″ | 44.30 |
| 3.25 | 5.248 | 63.5 | 10G | 2-1/2″ | 57.00 |
| 3.25 | 6.354 | 76.2 | 10G | 3″ | 69.70 |
Square Tubes Size Chart – C68700
| Size (mm) | Size (inch) | Weight (kg/m) |
|---|---|---|
| 19.05 x 1.22 | 3/4 x 18G | 0.75 |
| 12.7 x 1.22 | 1/2 x 18G | 0.48 |
| 30.0 x 1.22 | – | 1.20 |
| 25.4 x 1.22 | 1 x 18G | 0.99 |
| 38.10 x 1.22 | 1-1/2 x 18G | 1.54 |
Equivalent Grades – C68700 (ASTM B111)
| SPECIFICATIONS | Country | DESIGNATION |
|---|---|---|
| EN | Europe | CuZn20Al2 / CW702R |
| BS | United Kingdom | CZ 110 |
| JIS | Japan | C6870 T |
| DIN | German | 2.0460 |
| ISO | – | CuZn20Al2 |
| Russian | Russia | LAMs77-2-0.05 |
Standard Comparison – Chemical Composition
| Standard | Symbol | Cu | Al | As | Fe | Pb | Zn |
|---|---|---|---|---|---|---|---|
| ASTM B111 | C68700 | 76.0-79.0 | 1.8-2.5 | 0.02-0.06 | 0.06 | 0.07 | Rem |
| BS 2871 | CZ110 | 76.0-78.0 | 1.8-2.3 | 0.02-0.06 | 0.06 | 0.07 | Rem |
| DIN 1785 | CuZn20Al2 | 76.0-79.0 | 1.8-2.3 | 0.02-0.35 | 0.07 | 0.07 | Rem |
| JIS H3300 | C6870 | 76.0-79.0 | 1.8-2.5 | 0.02-0.06 | 0.06 | 0.07 | Rem |
| IS 1545 | CuZn21Al2As | 76.0-78.0 | 1.8-2.3 | 0.02-0.06 | 0.06 | 0.07 | Rem |
Mechanical Properties Comparison – ASTM B111 vs JIS
| Standard | Designation | Temper | Tensile min (ksi) | Yield min (ksi) | Elongation min % |
|---|---|---|---|---|---|
| ASTM | C68700 | O61 | 50 | 18 | – |
| JIS | C6871T-O | O61 | 36 | 13 | 40 |
Applications – C68700 Condenser Tubes
| Industry | Application |
|---|---|
| Power Plants | Surface condensers |
| Desalination Plants | Evaporators, distiller tubes |
| Refineries | Heat exchangers |
| Marine | Ferrules, cooling systems |
| General Industry | Heat exchanger tubes |
Quality Testing – Per ASTM B111 Requirements
| Test Method | Standard | Requirement |
|---|---|---|
| Expansion Test | ASTM B153 | 20% expansion, no cracking |
| Flattening Test | ASTM B968 | No defects in flattened area |
| Hydrostatic Test | ASTM B111 | 7000 psi fiber stress |
| Pneumatic Test | ASTM B111 | 60 psig for 5 seconds |
| Eddy Current Test | ASTM E243 | Per Practice E243 |
| Grain Size | ASTM E112 | 0.010-0.045 mm |
| Residual Stress | B154 or B858 | For non-annealed temper |
Temper Designations per ASTM B111
| Temper Code | Name | Description |
|---|---|---|
| O61 | Annealed | Fully recrystallized, grain size 0.010-0.045 mm |
| H55 | Light-drawn | Moderate cold work |
| H80 | Hard-drawn | Significant cold work |
| HR50 | Drawn and stress-relieved | For C71500/C71640 |
C68700 vs Other Copper Alloys: Which One Should You Choose?
Choosing the right copper alloy tube depends on your cooling medium, operating environment, corrosion requirements, and project budget. Below is a comparison of the most commonly used condenser tube materials.
| Alloy | Corrosion Resistance | Seawater Resistance | Thermal Conductivity | Cost | Typical Applications |
|---|---|---|---|---|---|
| C68700 Aluminum Brass | Excellent | Excellent | Excellent | Moderate | Surface condensers, seawater heat exchangers, desalination plants |
| C44300 Admiralty Brass | Good | Moderate | Excellent | Lower | Freshwater condensers, HVAC systems |
| C70600 90/10 Copper Nickel | Excellent | Outstanding | Good | Higher | Marine cooling systems, offshore platforms |
| C71500 70/30 Copper Nickel | Outstanding | Outstanding | Good | Highest | Naval vessels, offshore engineering, severe seawater service |
How to Choose the Right Alloy
| If Your Project Requires... | Recommended Material |
|---|---|
| High heat transfer efficiency | C68700 |
| Freshwater cooling systems | C44300 |
| Continuous seawater service | C70600 |
| High-flow seawater with severe corrosion | C71500 |
| Best balance of performance and cost | C68700 |
100% Quality Inspection Before Shipment
C68700 Tube Inspection
Inspection Equipment
| Equipment | Purpose |
|---|---|
| Optical Emission Spectrometer (OES) | Chemical composition analysis |
| Universal Testing Machine | Tensile, yield strength and elongation testing |
| Eddy Current Testing Equipment | Surface and internal defect detection |
| Hydrostatic Pressure Tester | Pressure resistance verification |
| Digital Micrometer & Vernier Caliper | Dimension inspection |
| Ultrasonic Thickness Gauge | Wall thickness measurement |
| Surface Roughness Tester | Surface quality inspection |
Packaging & Delivery
C68700 Heat Exchanger Brass Tube Packaging
Every C68700 aluminum brass tube is carefully packed to prevent damage during international transportation.
Export Packaging
| Packaging Method | Description |
|---|---|
| Plastic End Caps | Protect both tube ends from impact |
| PE Protective Film | Prevent scratches during handling |
| Waterproof Plastic Film | Moisture-proof packaging |
| Woven Bags | Standard export packing |
| Export Plywood Cases | Suitable for LCL shipments |
| Steel Frame Packing | Recommended for long tubes |
| Customized Labels | Customer logo and PO number available |
Production Lead Time
| Order Type | Lead Time |
|---|---|
| Stock Sizes | 3–7 Days |
| Standard Orders | 7–15 Days |
| Customized Tubes | 15–20 Days |
| Large Quantity Orders | 20–30 Days |
| U-Bend Processing | 15–25 Days |
| Urgent Orders | Please Contact Us |
Our Factory & Equipment
All ASTM C68700 tubes are produced and inspected on our in-house equipment, allowing full process control from billet casting to final packing.
Key equipment used for this lot:
• Induction melting furnace – precise alloying (Cu + Zn + Al + As)
• Horizontal continuous casting – uniform billet structure
• Extrusion press (800T / 1630T) – seamless tube forming
• Cold drawing bench (5–40m) – dimensional accuracy to ±0.02mm
• Online eddy current tester (FOERSTER / MAC) – 100% NDT
• Ultrasonic wall thickness gauge – real-time monitoring
• Annealing furnace (controlled atmosphere) – temper O61
In-house metrology: Micrometers, pin gauges, optical comparator, hardness tester (HV/HRB)
All equipment is calibrated quarterly. Production records are traceable by lot number.
Copper & Copper Alloy Products – Supply Range
| Product Form | Common Alloys / Grades | Size Range | Standards | Typical Applications |
|---|---|---|---|---|
| Tube / Pipe | C12200, C11000, C68700, C70600, C71500, C44300, C27000 | OD: 4mm – 219mm Wall: 0.5mm – 20mm Length: up to 15m |
ASTM B68, B75, B111, B280, B359, B466 | Heat exchangers, condensers, HVAC, plumbing, oil coolers |
| Plate / Sheet | C11000, C12200, C26000, C26800, C52100, C68700 | Thk: 0.5mm – 50mm Width: up to 1200mm Length: up to 4000mm |
ASTM B152, B169, B103, B465 | Electrical parts, roofing, gaskets, industrial panels |
| Rod / Bar | C11000, C26000, C36000, C46400, C48500, C63000 | Dia: 3mm – 120mm Length: 1m – 6m (or custom) |
ASTM B16, B124, B138, B150, B453 | Valve stems, shafts, fasteners, machined components |
| Wire | C11000, C16200, C17500, C26000, C52100, C64700 | Dia: 0.1mm – 12mm Coil weight: up to 100kg |
ASTM B1, B2, B3, B197, B206, B624 | Welding electrodes, electrical conductors, springs, mesh |
| Strip / Foil | C11000, C19400, C26000, C26800, C52100, C70250 | Thk: 0.05mm – 3.0mm Width: 5mm – 600mm |
ASTM B36, B465, B694, B888 | Connectors, terminals, battery tabs, shielding, stamping parts |
FAQ
Q1: What is ASTM B111 C68700?
A: ASTM B111 C68700 is an aluminum brass alloy (76-79% Cu, 1.8-2.5% Al) used for seamless condenser and heat exchanger tubes in surface condensers, evaporators, and heat exchangers per ASTM B111 specification.
Q2: What is the grain size requirement for C68700 per ASTM B111?
A: Per ASTM B111, annealed C68700 tubes (O61 temper) require an average grain size of 0.010 to 0.045 mm when tested per ASTM E112 at 75x magnification.
Q3: What is the expansion test requirement for C68700?
A: Per ASTM B153, C68700 tubes must withstand 20% expansion of original outside diameter with no cracking or rupture visible to the unaided eye.
Q4: What is the difference between C68700 and C44300?
A: C68700 (Aluminum Brass) contains 1.8-2.5% Al for seawater impingement resistance. C44300 (Admiralty Brass) contains 1% Sn and is limited to lower water velocities (below 2 m/s).
Q5: What sizes are available for C68700 tubes?
A: ASTM B111 C68700 tubes are available in OD from 4.76mm to 104.78mm, wall thickness from 0.508mm to 10mm, and length up to 15 meters straight length.
Q6: What are the EN equivalents of UNS C68700?
A: The European equivalents of UNS C68700 are EN CuZn20Al2 and EN CW702R. Other equivalents include BS CZ110, DIN 2.0460, and JIS C6870 T.
Q7: What testing is required per ASTM B111 for C68700?
A: Per ASTM B111, C68700 tubes require expansion test (B153) , eddy current test (E243) , grain size analysis (E112) , and optional hydrostatic or pneumatic test.
Q8: What is the price of C68700 aluminum brass tubes?
A: C68700 tubes are priced at approximately $10.60-10.75 USD per piece for standard sizes like 11mm OD x 0.80mm WT. Contact GNEE for bulk pricing.
Q9: What is the purpose of arsenic in C68700?
A: Arsenic (0.02-0.06%) in C68700 prevents dezincification – selective zinc leaching in seawater – extending tube life in marine service from months to 10+ years.
Q10: What is the hydrostatic test pressure for C68700?
A: Per ASTM B111, C68700 tubes are tested to 7000 psi (48 MPa) fiber stress using formula P=2St/(D-0.8t), with maximum test pressure of 1000 psi (7.0 MPa) unless specified.
Q11: What is the thermal conductivity of C68700?
A: UNS C68700 has a thermal conductivity of 58.0 BTU·in/hr·ft²·°F (100.4 W/m·K) at 68°F, making it suitable for heat exchangers and condensers.
Q12: What is the difference between O61 and other tempers?
A: O61 is the annealed temper per ASTM B111, requiring full recrystallization and grain size of 0.010-0.045 mm. H55 is light-drawn, H80 is hard-drawn.
Q13: What are C68700 tubes used for?
A: C68700 tubes are used for surface condensers, evaporators, heat exchangers, ferrules, and distiller tubes in power plants, desalination plants, refineries, and marine applications.
Q14: What is the density of C68700?
A: C68700 density is 8.33 g/cm³ (0.301 lb/in³) at 68°F, with specific gravity of 8.33.
Q15: Does GNEE supply custom sizes of C68700 tubes?
A: Yes, GNEE supplies C68700 tubes in custom OD (4.76-104.78mm), wall thickness, and length up to 15m. Contact GNEE with your specifications.
