ASTM A179 Extruded Finned Tubes
Product Overview
ASTM A179 Extruded Finned Tubes are high-performance heat transfer tubes manufactured from ASTM A179 seamless low-carbon steel tubes with an external aluminum fin sleeve mechanically extruded onto the base tube. During the extrusion process, the aluminum sleeve is plastically deformed under high pressure, forming integral fins while creating an exceptionally tight bond between the fin material and the tube surface.
Compared with welded finned tubes and embedded fin tubes, extruded finned tubes provide superior mechanical strength, enhanced environmental protection of the base tube, and excellent resistance to atmospheric corrosion. The continuous aluminum sleeve completely covers the steel tube surface, minimizing exposure to moisture and corrosive environments.
These finned tubes are widely used in air-cooled heat exchangers, economizers, waste heat recovery systems, HVAC equipment, condensers, radiators, and process cooling applications where high heat transfer efficiency and long operating life are required.
ASTM A179 Base Tube Specification
Standard
ASTM A179 / ASME SA179
Product Type
Cold Drawn Seamless Low-Carbon Steel Heat Exchanger Tube
Typical Applications
- Heat exchangers
- Condensers
- Economizers
- Air preheaters
- Boiler auxiliary systems
- Process cooling equipment
Chemical Composition of ASTM A179
| Element |
Composition (%) |
| Carbon (C) |
≤ 0.18 |
| Manganese (Mn) |
0.27 – 0.63 |
| Phosphorus (P) |
≤ 0.035 |
| Sulfur (S) |
≤ 0.035 |
The low carbon content provides excellent cold-forming capability, good weldability, and reliable thermal conductivity for heat transfer applications.
Mechanical Properties of ASTM A179
| Property |
Value |
| Tensile Strength |
≥ 325 MPa (47 ksi) |
| Yield Strength |
≥ 180 MPa (26 ksi) |
| Elongation |
≥ 35% |
| Hardness |
Typically ≤ 72 HRB |
These mechanical properties make ASTM A179 an economical and dependable material for medium-temperature heat transfer equipment.
Extruded Fin Construction
Base Tube Material
- ASTM A179 Carbon Steel
- Other materials available upon request
Fin Material
- Aluminum 1050
- Aluminum 1060
- Aluminum 1100
- Aluminum 6063
Manufacturing Process
- Aluminum sleeve is positioned over the ASTM A179 tube.
- Multiple rolling dies apply high radial pressure.
- Aluminum is extruded outward to form fins.
- The remaining aluminum layer completely encapsulates the steel tube.
This process creates a strong mechanical bond while protecting the base tube from external corrosion.
Typical Dimensions
Base Tube Size Range
| Outside Diameter |
Wall Thickness |
| 15.88 mm (5/8") |
1.2 – 3.0 mm |
| 19.05 mm (3/4") |
1.2 – 4.0 mm |
| 25.40 mm (1") |
1.5 – 5.0 mm |
| 31.75 mm (1-1/4") |
1.5 – 5.0 mm |
| 38.10 mm (1-1/2") |
2.0 – 5.0 mm |
| 50.80 mm (2") |
2.0 – 6.0 mm |
Fin Parameters
| Item |
Typical Range |
| Fin Height |
8 – 16 mm |
| Fin Thickness |
0.3 – 0.5 mm |
| Fin Density |
8 – 13 FPI |
| Fin Pitch |
2.0 – 3.2 mm |
