What Is Brass Tube?
Brass tube is drawn from copper-zinc alloys, with copper content typically ranging from 60 to 90 percent depending on the grade. The most common tube alloys are 70/30 cartridge brass (C26000), 85/15 red brass (C23000), and inhibited brasses such as admiralty brass (C44300) for heat exchanger duty. Brass tube combines moderate strength, good corrosion resistance, high thermal conductivity relative to most engineering metals, and excellent formability, which is why it appears in so many industries.
Advantages of Brass Tube
| Advantage | Practical Benefit |
|---|---|
| Corrosion resistance | Long life in water, steam, and many chemical services; dezincification-resistant grades available |
| Thermal conductivity | Efficient heat transfer in radiators, condensers, and heat exchangers |
| Formability | Easy bending, flaring, swaging, and coil forming without cracking in alpha grades |
| Joinability | Solders and brazes readily; compatible with standard fittings |
| Antimicrobial surface | Inherently antimicrobial, valued in hospitals and drinking-water systems |
| Aesthetic finish | Warm yellow color used in architectural and decorative hardware |
| Recyclability | Fully recyclable with no loss of properties |
Application Areas
Plumbing and Building Services
Brass tube is used for hot and cold water supply, gas lines, and fittings in high-end buildings, where its corrosion resistance, antimicrobial surface, and long service life justify the material cost. Red brass and 70/30 brass tubes are common in fixture supplies and valve connections.
HVAC and Refrigeration
In air-conditioning and refrigeration systems, brass tube appears in condenser and evaporator connections, capillary tubes, and small-diameter refrigerant lines. Its thermal conductivity and easy flaring make it practical for field installation, although copper tube remains dominant for long refrigerant runs.
Heat Exchangers and Condensers
Admiralty brass (C44300) and aluminum brass (C68700) tubes are standard in shell-and-tube condensers for power plants, refineries, and marine cooling systems operating with fresh or brackish cooling water. Arsenic additions inhibit dezincification and extend tube life.
Mechanical Engineering
Brass tube is drawn into bearing cages, pump liners, hydraulic and lubrication lines, and wear components where moderate strength, low friction, and corrosion resistance are required together.
Electrical and Electronic Equipment
Although less conductive than pure copper, brass tube is used for connector shells, heat sinks, relay components, and instrument conduits where cost, formability, and corrosion resistance matter more than maximum conductivity.
Marine Engineering
Naval brass and other inhibited brasses are used for small-bore seawater lines, cooler tubes, and fittings on vessels, selected for their resistance to saltwater corrosion. For high-velocity seawater duty, copper-nickel alloys are usually preferred.
Automotive
Brass tube is found in radiator cores, oil coolers, and heater tubes, where its thermal conductivity and solderability suit high-volume production. Modern vehicles increasingly use aluminum, but brass remains in heavy-duty and specialty cooling systems.
How to Select the Right Brass Tube
For water and general service, specify red brass C23000 or cartridge brass C26000 in the appropriate temper.
For condenser and heat exchanger tubes, specify admiralty brass C44300 (freshwater) or aluminum brass C68700 (seawater).
For severe marine duty, consider copper-nickel C70600 or C71500 instead of brass.
Check dezincification resistance if the water is acidic, saline, or aggressive.
Choose the temper by forming method: annealed for bending and flaring, drawn for stiffness.
Frequently Asked Questions
Q: Is brass tube safe for drinking water?
A: Yes, provided the alloy meets local lead-content limits for potable water. Modern low-lead brass alloys are used in drinking-water fittings and supply tubes.
Q: What is the difference between brass tube and copper tube?
A: Copper tube offers higher electrical and thermal conductivity and softer formability; brass tube offers higher strength, better machinability, and a harder surface at lower material cost.
Q: Can brass tube be bent without cracking?
A: Yes, in annealed temper and with the correct bending radius. Alpha brasses such as C26000 are very ductile; higher-zinc duplex brasses are more prone to cracking.
Q: Which brass tube is used for heat exchangers?
A: Admiralty brass (C44300) for fresh and brackish water, and aluminum brass (C68700) for seawater, both per ASTM B111.
Q: Does brass tube dezincify?
A: High-zinc brasses can dezincify in aggressive water. Inhibited grades with arsenic, such as C44300, resist this attack and are preferred for heat exchanger service.
Q: What tempers are available for brass tube?
A: Annealed (soft), light drawn, half-hard, and hard drawn. Annealed tube is standard for bending and flaring; drawn tempers give higher strength.
