A bimetallic G-type fin tube starts with a groove. A continuous helical channel gets machined into the base tube, an aluminium or copper strip is wound edge-on into that groove, and then a forming roller folds the parent metal shoulder back over the fin foot to lock it in place. Usually the fin and the tube underneath it are the same metal. Make them different instead, and that's a Bimetallic G-Type Fin Tube. The fin gets chosen for how well it conducts heat, the base tube gets chosen for how well it holds pressure and resists whatever is flowing past it, and neither choice has to give ground to the other.
Amardeep Steel Centre supplies bimetallic G-type fin tubes with the fin and base tube materials selected separately to suit the required thermal performance and service conditions. This construction follows the embedded G-Type design used in ourG Fin Tubes range, with different materials combined where the application requires it.
Technical Data
Specifications of Bimetallic G-Type Fin Tubes
Parameter | Specification |
|---|---|
Fin Type | G-Type, embedded and backfilled, bimetallic (fin and base tube materials differ) |
Fin Materials | Aluminium, Copper |
Base Tube Materials | Carbon Steel, Stainless Steel, Alloy Steel, Copper Alloys, Nickel Alloys |
Base Tube Outer Diameter | 15.88 mm to 50.80 mm |
Groove Depth | Approximately 0.4 mm, matched to base tube wall thickness |
Fin Density | 7 to 11 fins per inch |
Maximum Operating Temperature | Up to 450 degrees Celsius, subject to fin material, base tube material, bond construction and application conditions |
Documentation | Mill Test Certificate supplied with every order |
Chemical Composition of Bimetallic G-Type Fin Tubes
Material | Composition Note |
|---|---|
Aluminium Fin (1100 / 1050) | 99.0% minimum aluminium |
Copper Fin (C12200) | 99.9% minimum copper |
Carbon Steel Base Tube (A179) | 0.06% to 0.18% carbon |
Stainless Steel Base Tube (TP304) | 18.00% to 20.00% chromium, 8.00% to 10.50% nickel |
Mechanical Properties of G-Type Bimetallic Fin Tubes
Material | Specification / Condition | Tensile Strength (Min) | Yield Strength (Min) | Elongation (Min) |
|---|---|---|---|---|
Aluminium Fin | Aluminium 1100-O | 75 MPa | 20 MPa | 25% |
Copper Fin | C12200, Annealed | 220 MPa | 69 MPa | 35% |
Carbon Steel Base Tube | ASTM A179 | 325 MPa | 180 MPa | 35% |
Stainless Steel Base Tube | ASTM A249 TP304 | 515 MPa | 205 MPa | 35% |
Bimetallic G-Type Finned Tubes Dimension Chart
Bare Tube OD | Fin Height | FPI |
|---|---|---|
15.88 mm to 19.05 mm | 6.35 mm to 12.70 mm | 7 to 9 FPI |
25.40 mm to 31.75 mm | 12.70 mm to 19.05 mm | 8 to 10 FPI |
38.10 mm to 50.80 mm | 19.05 mm to 25.40 mm | 9 to 11 FPI |
Match your bare tube diameter against this chart for the standard fin height and density pairing.Share your drawing with our team if your project falls outside these ranges.
Applications of Bimetallic G-Type Fin Tubes
- Hot, Continuous Duty Air-Cooled Heat Exchangers: where wrapped or knurled fin types would eventually lose grip under sustained heat.
- Regularly Cleaned Fin Side Applications: the embedded bond holds up to repeated thermal cycling from cleaning cycles.
- Power Generation: process heat exchangers needing a corrosion-resistant base tube and a highly conductive fin together.
- Petrochemical Processing: aggressive process streams where the base tube material has to work harder than the fin metal.
Frequently Asked Questions
What is a bimetallic G-type fin tube?
A Bimetallic G-Type Fin Tube is an embedded G construction fin tube where the fin material is deliberately different from the base tube material, most often an aluminium fin on a carbon steel, stainless steel, or corrosion-resistant alloy base tube.
What is the difference between a mono- and a bimetallic G-type fin tube?
A mono G-type fin tube uses the same metal for the fin and the base tube. A bimetallic G-Type fin tube uses two different metals, so the fin can be optimised for conductivity while the base tube is optimised for pressure and corrosion resistance.
Is the fin material the same as the base tube material in a G-type fin tube?
Not necessarily. The fin material and the base tube material are two separate choices. In a mono build, they happen to match; in a bimetallic build, they are chosen independently, which is the whole point of specifying it as bimetallic.
What is the maximum operating temperature for Bimetallic G-Type Fin Tubes?
Bimetallic G-type fin tubes can be supplied for temperatures up to 450 degrees Celsius, subject to the fin material, base tube material, bond construction, wall thickness and applicable equipment design requirements. The final operating limit should be confirmed for the specified material combination and service conditions.
Which fin and base tube material combinations are available?
Amardeep Steel Centre supplies aluminium or copper fins on carbon steel, stainless steel, alloy steel, copper alloy, or nickel alloy base tubes, matched to your process fluid and thermal requirements.
Does Amardeep provide Mill Test Certificates with Bimetallic G-Type Fin Tubes?
Yes, every order ships with a mill test certificate covering the chemical and mechanical properties of both the fin and base tube materials used.
Why Choose Amardeep Steel Centre
Amardeep Steel Centre has manufactured and exported stainless steel and speciality tube products since 1982, with clients across more than 40 countries. Our bimetallic G-type fin tubes are built to your fin and base tube material requirements, and every order ships with full mill documentation.
Get in touch with our team with your project specification, or send an enquiry directly for a quote on Bimetallic G-Type Fin Tubes built to your requirements.
Request a QuoteRelated Products
G Fin Tubes, Rectangular Finned Tubes, Bimetallic L-Type Fin Tubes, KL Fin Tubes, and Finned Tubes.
