ASTM / B / 68 Bright Annealed Copper tube 5/8 , 1/2 , 3 / 8 and 1/4 inches
ASTM B68 covers seamless copper tube that is brightly annealed for use in applications requiring a smooth, clean surface and precise dimensions. These tubes are commonly used in plumbing, refrigeration, air conditioning, and industrial applications.
Specifications for ASTM B68 Bright Annealed Copper Tubes
• Standard: ASTM B68
• Material: Copper (typically C12200, 99.9% pure, phosphorus-deoxidized)
• Manufacturing Process: Seamless, Bright Annealed
• Surface Finish: Smooth, Oxide-free
• Temper: Annealed (soft, easily bendable)
Available Sizes (Nominal Outside Diameter - OD)
• 5/8 inch (0.625”)
• 1/2 inch (0.500”)
• 3/8 inch (0.375”)
• 1/4 inch (0.250”)
Wall Thickness, Pressure Ratings, Or Applications Of Bright Annealed Copper Tube:
Wall Thickness:
Bright annealed copper tubes are available in different standard sizes and wall thicknesses, typically classified under ASTM or other international standards. The most common standards include:
• ASTM B75 (General Engineering Applications)
• ASTM B68 (Seamless Copper Tube, Bright Annealed, for Refrigeration)
• ASTM B280 (Air Conditioning & Refrigeration)
• ASTM B88 (Water and Plumbing Applications)
Standard wall thickness varies by application:
• Type K (Thickest)
• Type L (Medium thickness)
• Type M (Thinnest)
• Refrigeration Tubing: Specified in OD and wall thickness (e.g., 1/4” OD x 0.032” wall)
Pressure Ratings:
The pressure rating depends on tube size, wall thickness, and operating temperature. Some general guidelines:
Higher wall thickness = Higher pressure rating
Annealed tubing has lower pressure ratings than hard-drawn tubing
Typical Ratings (for 100°F / 38°C):
• 1/4” OD, 0.032” wall: ~1,500 psi
• 3/8” OD, 0.032” wall: ~900 psi
• 1/2” OD, 0.035” wall: ~750 psi
• 1” OD, 0.045” wall: ~500 psi
For precise ratings, refer to ASTM B280, ASME B31.3, or manufacturer data.
Bright Annealed Copper Tubes application industries:
Bright Annealed Copper Tubes are widely used in various industries due to their high corrosion resistance, excellent thermal and electrical conductivity, and smooth, clean surface.
Bright Annealed Copper Tubes are used where clean, high-quality tubing is required, such as:
• HVAC & Refrigeration: Used in air conditioning systems, heat exchangers, and refrigeration units for efficient heat transfer. Ideal for condenser and evaporator coils due to their resistance to corrosion and smooth internal surface
• Medical Gas Lines: Essential for medical gas distribution in hospitals and clinics. Used in MRI cooling systems and laboratory equipment
• Plumbing & Water Lines: Commonly used in residential, commercial, and industrial plumbing systems. Suitable for carrying potable water due to their corrosion resistance and hygienic properties.
• Automotive Industry : Used in fuel lines, brake lines, and cooling systems due to their durability and heat resistance. Essential for manufacturing radiators and heater cores
• Electrical Industry : Used in electrical conductors, bus bars, and grounding systems due to their excellent conductivity. Preferred in transformers and switchgear components
• Industrial & Chemical Processing : Employed in chemical processing plants for transporting gases and liquids. Resistant to corrosion from acids and other chemicals
• Marine & Shipbuilding : Used in desalination plants and marine HVAC systems due to their resistance to seawater corrosion. Ideal for hydraulic and cooling systems in ships.
• Instrumentation & Laboratory Use: High-purity applications
• Oil & Gas Industry : Utilized in heat exchangers, condensers, and offshore piping systems. Preferred for high-pressure applications due to their strength and non-reactive nature.
• Renewable Energy : Used in solar water heaters and geothermal systems for efficient heat conduction. Essential heat exchangers for solar thermal power plants.